| Step | Hyp | Ref | Expression | 
						
							| 1 |  | unieq | ⊢ ( 𝑥  =  ∅  →  ∪  𝑥  =  ∪  ∅ ) | 
						
							| 2 |  | uni0 | ⊢ ∪  ∅  =  ∅ | 
						
							| 3 | 1 2 | eqtrdi | ⊢ ( 𝑥  =  ∅  →  ∪  𝑥  =  ∅ ) | 
						
							| 4 | 3 | ineq2d | ⊢ ( 𝑥  =  ∅  →  ( 𝑏  ∩  ∪  𝑥 )  =  ( 𝑏  ∩  ∅ ) ) | 
						
							| 5 |  | in0 | ⊢ ( 𝑏  ∩  ∅ )  =  ∅ | 
						
							| 6 | 4 5 | eqtrdi | ⊢ ( 𝑥  =  ∅  →  ( 𝑏  ∩  ∪  𝑥 )  =  ∅ ) | 
						
							| 7 | 6 | fveq2d | ⊢ ( 𝑥  =  ∅  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) )  =  ( ♯ ‘ ∅ ) ) | 
						
							| 8 |  | hash0 | ⊢ ( ♯ ‘ ∅ )  =  0 | 
						
							| 9 | 7 8 | eqtrdi | ⊢ ( 𝑥  =  ∅  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) )  =  0 ) | 
						
							| 10 | 9 | oveq2d | ⊢ ( 𝑥  =  ∅  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  ( ( ♯ ‘ 𝑏 )  −  0 ) ) | 
						
							| 11 |  | pweq | ⊢ ( 𝑥  =  ∅  →  𝒫  𝑥  =  𝒫  ∅ ) | 
						
							| 12 |  | pw0 | ⊢ 𝒫  ∅  =  { ∅ } | 
						
							| 13 | 11 12 | eqtrdi | ⊢ ( 𝑥  =  ∅  →  𝒫  𝑥  =  { ∅ } ) | 
						
							| 14 | 13 | sumeq1d | ⊢ ( 𝑥  =  ∅  →  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  { ∅ } ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 15 | 10 14 | eqeq12d | ⊢ ( 𝑥  =  ∅  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ 𝑏 )  −  0 )  =  Σ 𝑠  ∈  { ∅ } ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 16 | 15 | ralbidv | ⊢ ( 𝑥  =  ∅  →  ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  0 )  =  Σ 𝑠  ∈  { ∅ } ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 17 |  | unieq | ⊢ ( 𝑥  =  𝑦  →  ∪  𝑥  =  ∪  𝑦 ) | 
						
							| 18 | 17 | ineq2d | ⊢ ( 𝑥  =  𝑦  →  ( 𝑏  ∩  ∪  𝑥 )  =  ( 𝑏  ∩  ∪  𝑦 ) ) | 
						
							| 19 | 18 | fveq2d | ⊢ ( 𝑥  =  𝑦  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) )  =  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) ) | 
						
							| 20 | 19 | oveq2d | ⊢ ( 𝑥  =  𝑦  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) ) ) | 
						
							| 21 |  | pweq | ⊢ ( 𝑥  =  𝑦  →  𝒫  𝑥  =  𝒫  𝑦 ) | 
						
							| 22 | 21 | sumeq1d | ⊢ ( 𝑥  =  𝑦  →  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 23 | 20 22 | eqeq12d | ⊢ ( 𝑥  =  𝑦  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 24 | 23 | ralbidv | ⊢ ( 𝑥  =  𝑦  →  ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 25 |  | unieq | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  ∪  𝑥  =  ∪  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 26 |  | uniun | ⊢ ∪  ( 𝑦  ∪  { 𝑧 } )  =  ( ∪  𝑦  ∪  ∪  { 𝑧 } ) | 
						
							| 27 |  | unisnv | ⊢ ∪  { 𝑧 }  =  𝑧 | 
						
							| 28 | 27 | uneq2i | ⊢ ( ∪  𝑦  ∪  ∪  { 𝑧 } )  =  ( ∪  𝑦  ∪  𝑧 ) | 
						
							| 29 | 26 28 | eqtri | ⊢ ∪  ( 𝑦  ∪  { 𝑧 } )  =  ( ∪  𝑦  ∪  𝑧 ) | 
						
							| 30 | 25 29 | eqtrdi | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  ∪  𝑥  =  ( ∪  𝑦  ∪  𝑧 ) ) | 
						
							| 31 | 30 | ineq2d | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  ( 𝑏  ∩  ∪  𝑥 )  =  ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) | 
						
							| 32 | 31 | fveq2d | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) )  =  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) ) | 
						
							| 33 | 32 | oveq2d | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) ) ) | 
						
							| 34 |  | pweq | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  𝒫  𝑥  =  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 35 | 34 | sumeq1d | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 36 | 33 35 | eqeq12d | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 37 | 36 | ralbidv | ⊢ ( 𝑥  =  ( 𝑦  ∪  { 𝑧 } )  →  ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 38 |  | unieq | ⊢ ( 𝑥  =  𝐴  →  ∪  𝑥  =  ∪  𝐴 ) | 
						
							| 39 | 38 | ineq2d | ⊢ ( 𝑥  =  𝐴  →  ( 𝑏  ∩  ∪  𝑥 )  =  ( 𝑏  ∩  ∪  𝐴 ) ) | 
						
							| 40 | 39 | fveq2d | ⊢ ( 𝑥  =  𝐴  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) )  =  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) ) | 
						
							| 41 | 40 | oveq2d | ⊢ ( 𝑥  =  𝐴  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) ) ) | 
						
							| 42 |  | pweq | ⊢ ( 𝑥  =  𝐴  →  𝒫  𝑥  =  𝒫  𝐴 ) | 
						
							| 43 | 42 | sumeq1d | ⊢ ( 𝑥  =  𝐴  →  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 44 | 41 43 | eqeq12d | ⊢ ( 𝑥  =  𝐴  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 45 | 44 | ralbidv | ⊢ ( 𝑥  =  𝐴  →  ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑥 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑥 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 46 |  | hashcl | ⊢ ( 𝑏  ∈  Fin  →  ( ♯ ‘ 𝑏 )  ∈  ℕ0 ) | 
						
							| 47 | 46 | nn0cnd | ⊢ ( 𝑏  ∈  Fin  →  ( ♯ ‘ 𝑏 )  ∈  ℂ ) | 
						
							| 48 | 47 | mullidd | ⊢ ( 𝑏  ∈  Fin  →  ( 1  ·  ( ♯ ‘ 𝑏 ) )  =  ( ♯ ‘ 𝑏 ) ) | 
						
							| 49 |  | 0ex | ⊢ ∅  ∈  V | 
						
							| 50 | 48 47 | eqeltrd | ⊢ ( 𝑏  ∈  Fin  →  ( 1  ·  ( ♯ ‘ 𝑏 ) )  ∈  ℂ ) | 
						
							| 51 |  | fveq2 | ⊢ ( 𝑠  =  ∅  →  ( ♯ ‘ 𝑠 )  =  ( ♯ ‘ ∅ ) ) | 
						
							| 52 | 51 8 | eqtrdi | ⊢ ( 𝑠  =  ∅  →  ( ♯ ‘ 𝑠 )  =  0 ) | 
						
							| 53 | 52 | oveq2d | ⊢ ( 𝑠  =  ∅  →  ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  =  ( - 1 ↑ 0 ) ) | 
						
							| 54 |  | neg1cn | ⊢ - 1  ∈  ℂ | 
						
							| 55 |  | exp0 | ⊢ ( - 1  ∈  ℂ  →  ( - 1 ↑ 0 )  =  1 ) | 
						
							| 56 | 54 55 | ax-mp | ⊢ ( - 1 ↑ 0 )  =  1 | 
						
							| 57 | 53 56 | eqtrdi | ⊢ ( 𝑠  =  ∅  →  ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  =  1 ) | 
						
							| 58 |  | rint0 | ⊢ ( 𝑠  =  ∅  →  ( 𝑏  ∩  ∩  𝑠 )  =  𝑏 ) | 
						
							| 59 | 58 | fveq2d | ⊢ ( 𝑠  =  ∅  →  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) )  =  ( ♯ ‘ 𝑏 ) ) | 
						
							| 60 | 57 59 | oveq12d | ⊢ ( 𝑠  =  ∅  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  ( 1  ·  ( ♯ ‘ 𝑏 ) ) ) | 
						
							| 61 | 60 | sumsn | ⊢ ( ( ∅  ∈  V  ∧  ( 1  ·  ( ♯ ‘ 𝑏 ) )  ∈  ℂ )  →  Σ 𝑠  ∈  { ∅ } ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  ( 1  ·  ( ♯ ‘ 𝑏 ) ) ) | 
						
							| 62 | 49 50 61 | sylancr | ⊢ ( 𝑏  ∈  Fin  →  Σ 𝑠  ∈  { ∅ } ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  ( 1  ·  ( ♯ ‘ 𝑏 ) ) ) | 
						
							| 63 | 47 | subid1d | ⊢ ( 𝑏  ∈  Fin  →  ( ( ♯ ‘ 𝑏 )  −  0 )  =  ( ♯ ‘ 𝑏 ) ) | 
						
							| 64 | 48 62 63 | 3eqtr4rd | ⊢ ( 𝑏  ∈  Fin  →  ( ( ♯ ‘ 𝑏 )  −  0 )  =  Σ 𝑠  ∈  { ∅ } ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 65 | 64 | rgen | ⊢ ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  0 )  =  Σ 𝑠  ∈  { ∅ } ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) | 
						
							| 66 |  | fveq2 | ⊢ ( 𝑏  =  𝑥  →  ( ♯ ‘ 𝑏 )  =  ( ♯ ‘ 𝑥 ) ) | 
						
							| 67 |  | ineq1 | ⊢ ( 𝑏  =  𝑥  →  ( 𝑏  ∩  ∪  𝑦 )  =  ( 𝑥  ∩  ∪  𝑦 ) ) | 
						
							| 68 | 67 | fveq2d | ⊢ ( 𝑏  =  𝑥  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) )  =  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) ) | 
						
							| 69 | 66 68 | oveq12d | ⊢ ( 𝑏  =  𝑥  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) ) ) | 
						
							| 70 |  | simpl | ⊢ ( ( 𝑏  =  𝑥  ∧  𝑠  ∈  𝒫  𝑦 )  →  𝑏  =  𝑥 ) | 
						
							| 71 | 70 | ineq1d | ⊢ ( ( 𝑏  =  𝑥  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( 𝑏  ∩  ∩  𝑠 )  =  ( 𝑥  ∩  ∩  𝑠 ) ) | 
						
							| 72 | 71 | fveq2d | ⊢ ( ( 𝑏  =  𝑥  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) )  =  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) | 
						
							| 73 | 72 | oveq2d | ⊢ ( ( 𝑏  =  𝑥  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 74 | 73 | sumeq2dv | ⊢ ( 𝑏  =  𝑥  →  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 75 | 69 74 | eqeq12d | ⊢ ( 𝑏  =  𝑥  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 76 | 75 | rspcva | ⊢ ( ( 𝑥  ∈  Fin  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 77 | 76 | adantll | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 78 |  | simpr | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  𝑥  ∈  Fin ) | 
						
							| 79 |  | inss1 | ⊢ ( 𝑥  ∩  𝑧 )  ⊆  𝑥 | 
						
							| 80 |  | ssfi | ⊢ ( ( 𝑥  ∈  Fin  ∧  ( 𝑥  ∩  𝑧 )  ⊆  𝑥 )  →  ( 𝑥  ∩  𝑧 )  ∈  Fin ) | 
						
							| 81 | 78 79 80 | sylancl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( 𝑥  ∩  𝑧 )  ∈  Fin ) | 
						
							| 82 |  | fveq2 | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( ♯ ‘ 𝑏 )  =  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) ) ) | 
						
							| 83 |  | ineq1 | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( 𝑏  ∩  ∪  𝑦 )  =  ( ( 𝑥  ∩  𝑧 )  ∩  ∪  𝑦 ) ) | 
						
							| 84 |  | in32 | ⊢ ( ( 𝑥  ∩  𝑧 )  ∩  ∪  𝑦 )  =  ( ( 𝑥  ∩  ∪  𝑦 )  ∩  𝑧 ) | 
						
							| 85 |  | inass | ⊢ ( ( 𝑥  ∩  ∪  𝑦 )  ∩  𝑧 )  =  ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) | 
						
							| 86 | 84 85 | eqtri | ⊢ ( ( 𝑥  ∩  𝑧 )  ∩  ∪  𝑦 )  =  ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) | 
						
							| 87 | 83 86 | eqtrdi | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( 𝑏  ∩  ∪  𝑦 )  =  ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) | 
						
							| 88 | 87 | fveq2d | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) )  =  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) | 
						
							| 89 | 82 88 | oveq12d | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) ) | 
						
							| 90 |  | ineq1 | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( 𝑏  ∩  ∩  𝑠 )  =  ( ( 𝑥  ∩  𝑧 )  ∩  ∩  𝑠 ) ) | 
						
							| 91 |  | in32 | ⊢ ( ( 𝑥  ∩  𝑧 )  ∩  ∩  𝑠 )  =  ( ( 𝑥  ∩  ∩  𝑠 )  ∩  𝑧 ) | 
						
							| 92 |  | inass | ⊢ ( ( 𝑥  ∩  ∩  𝑠 )  ∩  𝑧 )  =  ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) | 
						
							| 93 | 91 92 | eqtri | ⊢ ( ( 𝑥  ∩  𝑧 )  ∩  ∩  𝑠 )  =  ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) | 
						
							| 94 | 90 93 | eqtrdi | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( 𝑏  ∩  ∩  𝑠 )  =  ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) | 
						
							| 95 | 94 | fveq2d | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) )  =  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) | 
						
							| 96 | 95 | oveq2d | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 97 | 96 | sumeq2sdv | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 98 | 89 97 | eqeq12d | ⊢ ( 𝑏  =  ( 𝑥  ∩  𝑧 )  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 99 | 98 | rspcva | ⊢ ( ( ( 𝑥  ∩  𝑧 )  ∈  Fin  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 100 | 81 99 | sylan | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 101 | 77 100 | oveq12d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  ( ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) )  −  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) )  =  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  −  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 102 |  | inss1 | ⊢ ( 𝑥  ∩  ∪  𝑦 )  ⊆  𝑥 | 
						
							| 103 |  | ssfi | ⊢ ( ( 𝑥  ∈  Fin  ∧  ( 𝑥  ∩  ∪  𝑦 )  ⊆  𝑥 )  →  ( 𝑥  ∩  ∪  𝑦 )  ∈  Fin ) | 
						
							| 104 | 78 102 103 | sylancl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( 𝑥  ∩  ∪  𝑦 )  ∈  Fin ) | 
						
							| 105 |  | hashcl | ⊢ ( ( 𝑥  ∩  ∪  𝑦 )  ∈  Fin  →  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  ∈  ℕ0 ) | 
						
							| 106 | 104 105 | syl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  ∈  ℕ0 ) | 
						
							| 107 | 106 | nn0cnd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  ∈  ℂ ) | 
						
							| 108 |  | hashcl | ⊢ ( ( 𝑥  ∩  𝑧 )  ∈  Fin  →  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  ∈  ℕ0 ) | 
						
							| 109 | 81 108 | syl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  ∈  ℕ0 ) | 
						
							| 110 | 109 | nn0cnd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  ∈  ℂ ) | 
						
							| 111 |  | inss1 | ⊢ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) )  ⊆  𝑥 | 
						
							| 112 |  | ssfi | ⊢ ( ( 𝑥  ∈  Fin  ∧  ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) )  ⊆  𝑥 )  →  ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) )  ∈  Fin ) | 
						
							| 113 | 78 111 112 | sylancl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) )  ∈  Fin ) | 
						
							| 114 |  | hashcl | ⊢ ( ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) )  ∈  Fin  →  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) )  ∈  ℕ0 ) | 
						
							| 115 | 113 114 | syl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) )  ∈  ℕ0 ) | 
						
							| 116 | 115 | nn0cnd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) )  ∈  ℂ ) | 
						
							| 117 |  | hashun3 | ⊢ ( ( ( 𝑥  ∩  ∪  𝑦 )  ∈  Fin  ∧  ( 𝑥  ∩  𝑧 )  ∈  Fin )  →  ( ♯ ‘ ( ( 𝑥  ∩  ∪  𝑦 )  ∪  ( 𝑥  ∩  𝑧 ) ) )  =  ( ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) ) )  −  ( ♯ ‘ ( ( 𝑥  ∩  ∪  𝑦 )  ∩  ( 𝑥  ∩  𝑧 ) ) ) ) ) | 
						
							| 118 | 104 81 117 | syl2anc | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( ( 𝑥  ∩  ∪  𝑦 )  ∪  ( 𝑥  ∩  𝑧 ) ) )  =  ( ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) ) )  −  ( ♯ ‘ ( ( 𝑥  ∩  ∪  𝑦 )  ∩  ( 𝑥  ∩  𝑧 ) ) ) ) ) | 
						
							| 119 |  | indi | ⊢ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) )  =  ( ( 𝑥  ∩  ∪  𝑦 )  ∪  ( 𝑥  ∩  𝑧 ) ) | 
						
							| 120 | 119 | fveq2i | ⊢ ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) )  =  ( ♯ ‘ ( ( 𝑥  ∩  ∪  𝑦 )  ∪  ( 𝑥  ∩  𝑧 ) ) ) | 
						
							| 121 |  | inindi | ⊢ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) )  =  ( ( 𝑥  ∩  ∪  𝑦 )  ∩  ( 𝑥  ∩  𝑧 ) ) | 
						
							| 122 | 121 | fveq2i | ⊢ ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) )  =  ( ♯ ‘ ( ( 𝑥  ∩  ∪  𝑦 )  ∩  ( 𝑥  ∩  𝑧 ) ) ) | 
						
							| 123 | 122 | oveq2i | ⊢ ( ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) )  =  ( ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) ) )  −  ( ♯ ‘ ( ( 𝑥  ∩  ∪  𝑦 )  ∩  ( 𝑥  ∩  𝑧 ) ) ) ) | 
						
							| 124 | 118 120 123 | 3eqtr4g | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) )  =  ( ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ♯ ‘ ( 𝑥  ∩  𝑧 ) ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) ) | 
						
							| 125 | 107 110 116 124 | assraddsubd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) )  =  ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 126 | 125 | oveq2d | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  ( ( ♯ ‘ 𝑥 )  −  ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) ) ) ) | 
						
							| 127 |  | hashcl | ⊢ ( 𝑥  ∈  Fin  →  ( ♯ ‘ 𝑥 )  ∈  ℕ0 ) | 
						
							| 128 | 127 | adantl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ 𝑥 )  ∈  ℕ0 ) | 
						
							| 129 | 128 | nn0cnd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ♯ ‘ 𝑥 )  ∈  ℂ ) | 
						
							| 130 | 110 116 | subcld | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) )  ∈  ℂ ) | 
						
							| 131 | 129 107 130 | subsub4d | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) )  −  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) )  =  ( ( ♯ ‘ 𝑥 )  −  ( ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) )  +  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) ) ) ) | 
						
							| 132 | 126 131 | eqtr4d | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  ( ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) )  −  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 133 | 132 | adantr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  ( ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ∪  𝑦 ) ) )  −  ( ( ♯ ‘ ( 𝑥  ∩  𝑧 ) )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 134 |  | disjdif | ⊢ ( 𝒫  𝑦  ∩  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  =  ∅ | 
						
							| 135 | 134 | a1i | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( 𝒫  𝑦  ∩  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  =  ∅ ) | 
						
							| 136 |  | ssun1 | ⊢ 𝑦  ⊆  ( 𝑦  ∪  { 𝑧 } ) | 
						
							| 137 | 136 | sspwi | ⊢ 𝒫  𝑦  ⊆  𝒫  ( 𝑦  ∪  { 𝑧 } ) | 
						
							| 138 |  | undif | ⊢ ( 𝒫  𝑦  ⊆  𝒫  ( 𝑦  ∪  { 𝑧 } )  ↔  ( 𝒫  𝑦  ∪  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  =  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 139 | 137 138 | mpbi | ⊢ ( 𝒫  𝑦  ∪  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  =  𝒫  ( 𝑦  ∪  { 𝑧 } ) | 
						
							| 140 | 139 | eqcomi | ⊢ 𝒫  ( 𝑦  ∪  { 𝑧 } )  =  ( 𝒫  𝑦  ∪  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) | 
						
							| 141 | 140 | a1i | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  𝒫  ( 𝑦  ∪  { 𝑧 } )  =  ( 𝒫  𝑦  ∪  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) ) | 
						
							| 142 |  | simpll | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  𝑦  ∈  Fin ) | 
						
							| 143 |  | snfi | ⊢ { 𝑧 }  ∈  Fin | 
						
							| 144 |  | unfi | ⊢ ( ( 𝑦  ∈  Fin  ∧  { 𝑧 }  ∈  Fin )  →  ( 𝑦  ∪  { 𝑧 } )  ∈  Fin ) | 
						
							| 145 | 142 143 144 | sylancl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( 𝑦  ∪  { 𝑧 } )  ∈  Fin ) | 
						
							| 146 |  | pwfi | ⊢ ( ( 𝑦  ∪  { 𝑧 } )  ∈  Fin  ↔  𝒫  ( 𝑦  ∪  { 𝑧 } )  ∈  Fin ) | 
						
							| 147 | 145 146 | sylib | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  𝒫  ( 𝑦  ∪  { 𝑧 } )  ∈  Fin ) | 
						
							| 148 | 54 | a1i | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  - 1  ∈  ℂ ) | 
						
							| 149 |  | elpwi | ⊢ ( 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } )  →  𝑠  ⊆  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 150 |  | ssfi | ⊢ ( ( ( 𝑦  ∪  { 𝑧 } )  ∈  Fin  ∧  𝑠  ⊆  ( 𝑦  ∪  { 𝑧 } ) )  →  𝑠  ∈  Fin ) | 
						
							| 151 | 145 149 150 | syl2an | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  𝑠  ∈  Fin ) | 
						
							| 152 |  | hashcl | ⊢ ( 𝑠  ∈  Fin  →  ( ♯ ‘ 𝑠 )  ∈  ℕ0 ) | 
						
							| 153 | 151 152 | syl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( ♯ ‘ 𝑠 )  ∈  ℕ0 ) | 
						
							| 154 | 148 153 | expcld | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ∈  ℂ ) | 
						
							| 155 |  | simplr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  𝑥  ∈  Fin ) | 
						
							| 156 |  | inss1 | ⊢ ( 𝑥  ∩  ∩  𝑠 )  ⊆  𝑥 | 
						
							| 157 |  | ssfi | ⊢ ( ( 𝑥  ∈  Fin  ∧  ( 𝑥  ∩  ∩  𝑠 )  ⊆  𝑥 )  →  ( 𝑥  ∩  ∩  𝑠 )  ∈  Fin ) | 
						
							| 158 | 155 156 157 | sylancl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( 𝑥  ∩  ∩  𝑠 )  ∈  Fin ) | 
						
							| 159 |  | hashcl | ⊢ ( ( 𝑥  ∩  ∩  𝑠 )  ∈  Fin  →  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) )  ∈  ℕ0 ) | 
						
							| 160 | 158 159 | syl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) )  ∈  ℕ0 ) | 
						
							| 161 | 160 | nn0cnd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) )  ∈  ℂ ) | 
						
							| 162 | 154 161 | mulcld | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  ∈  ℂ ) | 
						
							| 163 | 135 141 147 162 | fsumsplit | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  =  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  +  Σ 𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 164 |  | fveq2 | ⊢ ( 𝑠  =  ( 𝑡  ∪  { 𝑧 } )  →  ( ♯ ‘ 𝑠 )  =  ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) ) | 
						
							| 165 | 164 | oveq2d | ⊢ ( 𝑠  =  ( 𝑡  ∪  { 𝑧 } )  →  ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  =  ( - 1 ↑ ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) ) ) | 
						
							| 166 |  | inteq | ⊢ ( 𝑠  =  ( 𝑡  ∪  { 𝑧 } )  →  ∩  𝑠  =  ∩  ( 𝑡  ∪  { 𝑧 } ) ) | 
						
							| 167 |  | vex | ⊢ 𝑧  ∈  V | 
						
							| 168 | 167 | intunsn | ⊢ ∩  ( 𝑡  ∪  { 𝑧 } )  =  ( ∩  𝑡  ∩  𝑧 ) | 
						
							| 169 | 166 168 | eqtrdi | ⊢ ( 𝑠  =  ( 𝑡  ∪  { 𝑧 } )  →  ∩  𝑠  =  ( ∩  𝑡  ∩  𝑧 ) ) | 
						
							| 170 | 169 | ineq2d | ⊢ ( 𝑠  =  ( 𝑡  ∪  { 𝑧 } )  →  ( 𝑥  ∩  ∩  𝑠 )  =  ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) ) | 
						
							| 171 | 170 | fveq2d | ⊢ ( 𝑠  =  ( 𝑡  ∪  { 𝑧 } )  →  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) )  =  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) ) ) | 
						
							| 172 | 165 171 | oveq12d | ⊢ ( 𝑠  =  ( 𝑡  ∪  { 𝑧 } )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  =  ( ( - 1 ↑ ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) ) ) ) | 
						
							| 173 |  | pwfi | ⊢ ( 𝑦  ∈  Fin  ↔  𝒫  𝑦  ∈  Fin ) | 
						
							| 174 | 142 173 | sylib | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  𝒫  𝑦  ∈  Fin ) | 
						
							| 175 |  | eqid | ⊢ ( 𝑢  ∈  𝒫  𝑦  ↦  ( 𝑢  ∪  { 𝑧 } ) )  =  ( 𝑢  ∈  𝒫  𝑦  ↦  ( 𝑢  ∪  { 𝑧 } ) ) | 
						
							| 176 |  | elpwi | ⊢ ( 𝑢  ∈  𝒫  𝑦  →  𝑢  ⊆  𝑦 ) | 
						
							| 177 | 176 | adantl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  𝑢  ⊆  𝑦 ) | 
						
							| 178 |  | unss1 | ⊢ ( 𝑢  ⊆  𝑦  →  ( 𝑢  ∪  { 𝑧 } )  ⊆  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 179 | 177 178 | syl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  ( 𝑢  ∪  { 𝑧 } )  ⊆  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 180 |  | vex | ⊢ 𝑢  ∈  V | 
						
							| 181 |  | vsnex | ⊢ { 𝑧 }  ∈  V | 
						
							| 182 | 180 181 | unex | ⊢ ( 𝑢  ∪  { 𝑧 } )  ∈  V | 
						
							| 183 | 182 | elpw | ⊢ ( ( 𝑢  ∪  { 𝑧 } )  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } )  ↔  ( 𝑢  ∪  { 𝑧 } )  ⊆  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 184 | 179 183 | sylibr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  ( 𝑢  ∪  { 𝑧 } )  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 185 |  | simpllr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  ¬  𝑧  ∈  𝑦 ) | 
						
							| 186 |  | elpwi | ⊢ ( ( 𝑢  ∪  { 𝑧 } )  ∈  𝒫  𝑦  →  ( 𝑢  ∪  { 𝑧 } )  ⊆  𝑦 ) | 
						
							| 187 |  | ssun2 | ⊢ { 𝑧 }  ⊆  ( 𝑢  ∪  { 𝑧 } ) | 
						
							| 188 | 167 | snss | ⊢ ( 𝑧  ∈  ( 𝑢  ∪  { 𝑧 } )  ↔  { 𝑧 }  ⊆  ( 𝑢  ∪  { 𝑧 } ) ) | 
						
							| 189 | 187 188 | mpbir | ⊢ 𝑧  ∈  ( 𝑢  ∪  { 𝑧 } ) | 
						
							| 190 | 189 | a1i | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  𝑧  ∈  ( 𝑢  ∪  { 𝑧 } ) ) | 
						
							| 191 |  | ssel | ⊢ ( ( 𝑢  ∪  { 𝑧 } )  ⊆  𝑦  →  ( 𝑧  ∈  ( 𝑢  ∪  { 𝑧 } )  →  𝑧  ∈  𝑦 ) ) | 
						
							| 192 | 186 190 191 | syl2imc | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  ( ( 𝑢  ∪  { 𝑧 } )  ∈  𝒫  𝑦  →  𝑧  ∈  𝑦 ) ) | 
						
							| 193 | 185 192 | mtod | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  ¬  ( 𝑢  ∪  { 𝑧 } )  ∈  𝒫  𝑦 ) | 
						
							| 194 | 184 193 | eldifd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑢  ∈  𝒫  𝑦 )  →  ( 𝑢  ∪  { 𝑧 } )  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) | 
						
							| 195 |  | eldifi | ⊢ ( 𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 )  →  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 196 | 195 | adantl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  →  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 197 | 196 | elpwid | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  →  𝑠  ⊆  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 198 |  | uncom | ⊢ ( 𝑦  ∪  { 𝑧 } )  =  ( { 𝑧 }  ∪  𝑦 ) | 
						
							| 199 | 197 198 | sseqtrdi | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  →  𝑠  ⊆  ( { 𝑧 }  ∪  𝑦 ) ) | 
						
							| 200 |  | ssundif | ⊢ ( 𝑠  ⊆  ( { 𝑧 }  ∪  𝑦 )  ↔  ( 𝑠  ∖  { 𝑧 } )  ⊆  𝑦 ) | 
						
							| 201 | 199 200 | sylib | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  →  ( 𝑠  ∖  { 𝑧 } )  ⊆  𝑦 ) | 
						
							| 202 |  | vex | ⊢ 𝑦  ∈  V | 
						
							| 203 | 202 | elpw2 | ⊢ ( ( 𝑠  ∖  { 𝑧 } )  ∈  𝒫  𝑦  ↔  ( 𝑠  ∖  { 𝑧 } )  ⊆  𝑦 ) | 
						
							| 204 | 201 203 | sylibr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  →  ( 𝑠  ∖  { 𝑧 } )  ∈  𝒫  𝑦 ) | 
						
							| 205 |  | elpwunsn | ⊢ ( 𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 )  →  𝑧  ∈  𝑠 ) | 
						
							| 206 | 205 | ad2antll | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  𝑧  ∈  𝑠 ) | 
						
							| 207 | 206 | snssd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  { 𝑧 }  ⊆  𝑠 ) | 
						
							| 208 |  | ssequn2 | ⊢ ( { 𝑧 }  ⊆  𝑠  ↔  ( 𝑠  ∪  { 𝑧 } )  =  𝑠 ) | 
						
							| 209 | 207 208 | sylib | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  ( 𝑠  ∪  { 𝑧 } )  =  𝑠 ) | 
						
							| 210 | 209 | eqcomd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  𝑠  =  ( 𝑠  ∪  { 𝑧 } ) ) | 
						
							| 211 |  | uneq1 | ⊢ ( 𝑢  =  ( 𝑠  ∖  { 𝑧 } )  →  ( 𝑢  ∪  { 𝑧 } )  =  ( ( 𝑠  ∖  { 𝑧 } )  ∪  { 𝑧 } ) ) | 
						
							| 212 |  | undif1 | ⊢ ( ( 𝑠  ∖  { 𝑧 } )  ∪  { 𝑧 } )  =  ( 𝑠  ∪  { 𝑧 } ) | 
						
							| 213 | 211 212 | eqtrdi | ⊢ ( 𝑢  =  ( 𝑠  ∖  { 𝑧 } )  →  ( 𝑢  ∪  { 𝑧 } )  =  ( 𝑠  ∪  { 𝑧 } ) ) | 
						
							| 214 | 213 | eqeq2d | ⊢ ( 𝑢  =  ( 𝑠  ∖  { 𝑧 } )  →  ( 𝑠  =  ( 𝑢  ∪  { 𝑧 } )  ↔  𝑠  =  ( 𝑠  ∪  { 𝑧 } ) ) ) | 
						
							| 215 | 210 214 | syl5ibrcom | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  ( 𝑢  =  ( 𝑠  ∖  { 𝑧 } )  →  𝑠  =  ( 𝑢  ∪  { 𝑧 } ) ) ) | 
						
							| 216 | 176 | ad2antrl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  𝑢  ⊆  𝑦 ) | 
						
							| 217 |  | simpllr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  ¬  𝑧  ∈  𝑦 ) | 
						
							| 218 | 216 217 | ssneldd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  ¬  𝑧  ∈  𝑢 ) | 
						
							| 219 |  | difsnb | ⊢ ( ¬  𝑧  ∈  𝑢  ↔  ( 𝑢  ∖  { 𝑧 } )  =  𝑢 ) | 
						
							| 220 | 218 219 | sylib | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  ( 𝑢  ∖  { 𝑧 } )  =  𝑢 ) | 
						
							| 221 | 220 | eqcomd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  𝑢  =  ( 𝑢  ∖  { 𝑧 } ) ) | 
						
							| 222 |  | difeq1 | ⊢ ( 𝑠  =  ( 𝑢  ∪  { 𝑧 } )  →  ( 𝑠  ∖  { 𝑧 } )  =  ( ( 𝑢  ∪  { 𝑧 } )  ∖  { 𝑧 } ) ) | 
						
							| 223 |  | difun2 | ⊢ ( ( 𝑢  ∪  { 𝑧 } )  ∖  { 𝑧 } )  =  ( 𝑢  ∖  { 𝑧 } ) | 
						
							| 224 | 222 223 | eqtrdi | ⊢ ( 𝑠  =  ( 𝑢  ∪  { 𝑧 } )  →  ( 𝑠  ∖  { 𝑧 } )  =  ( 𝑢  ∖  { 𝑧 } ) ) | 
						
							| 225 | 224 | eqeq2d | ⊢ ( 𝑠  =  ( 𝑢  ∪  { 𝑧 } )  →  ( 𝑢  =  ( 𝑠  ∖  { 𝑧 } )  ↔  𝑢  =  ( 𝑢  ∖  { 𝑧 } ) ) ) | 
						
							| 226 | 221 225 | syl5ibrcom | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  ( 𝑠  =  ( 𝑢  ∪  { 𝑧 } )  →  𝑢  =  ( 𝑠  ∖  { 𝑧 } ) ) ) | 
						
							| 227 | 215 226 | impbid | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ( 𝑢  ∈  𝒫  𝑦  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) )  →  ( 𝑢  =  ( 𝑠  ∖  { 𝑧 } )  ↔  𝑠  =  ( 𝑢  ∪  { 𝑧 } ) ) ) | 
						
							| 228 | 175 194 204 227 | f1o2d | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( 𝑢  ∈  𝒫  𝑦  ↦  ( 𝑢  ∪  { 𝑧 } ) ) : 𝒫  𝑦 –1-1-onto→ ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ) | 
						
							| 229 |  | uneq1 | ⊢ ( 𝑢  =  𝑡  →  ( 𝑢  ∪  { 𝑧 } )  =  ( 𝑡  ∪  { 𝑧 } ) ) | 
						
							| 230 |  | vex | ⊢ 𝑡  ∈  V | 
						
							| 231 | 230 181 | unex | ⊢ ( 𝑡  ∪  { 𝑧 } )  ∈  V | 
						
							| 232 | 229 175 231 | fvmpt | ⊢ ( 𝑡  ∈  𝒫  𝑦  →  ( ( 𝑢  ∈  𝒫  𝑦  ↦  ( 𝑢  ∪  { 𝑧 } ) ) ‘ 𝑡 )  =  ( 𝑡  ∪  { 𝑧 } ) ) | 
						
							| 233 | 232 | adantl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑡  ∈  𝒫  𝑦 )  →  ( ( 𝑢  ∈  𝒫  𝑦  ↦  ( 𝑢  ∪  { 𝑧 } ) ) ‘ 𝑡 )  =  ( 𝑡  ∪  { 𝑧 } ) ) | 
						
							| 234 | 195 162 | sylan2 | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  ∈  ℂ ) | 
						
							| 235 | 172 174 228 233 234 | fsumf1o | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  =  Σ 𝑡  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) ) ) ) | 
						
							| 236 |  | uneq1 | ⊢ ( 𝑡  =  𝑠  →  ( 𝑡  ∪  { 𝑧 } )  =  ( 𝑠  ∪  { 𝑧 } ) ) | 
						
							| 237 | 236 | fveq2d | ⊢ ( 𝑡  =  𝑠  →  ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) )  =  ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) ) | 
						
							| 238 | 237 | oveq2d | ⊢ ( 𝑡  =  𝑠  →  ( - 1 ↑ ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) )  =  ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) ) ) | 
						
							| 239 |  | inteq | ⊢ ( 𝑡  =  𝑠  →  ∩  𝑡  =  ∩  𝑠 ) | 
						
							| 240 | 239 | ineq1d | ⊢ ( 𝑡  =  𝑠  →  ( ∩  𝑡  ∩  𝑧 )  =  ( ∩  𝑠  ∩  𝑧 ) ) | 
						
							| 241 | 240 | ineq2d | ⊢ ( 𝑡  =  𝑠  →  ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) )  =  ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) | 
						
							| 242 | 241 | fveq2d | ⊢ ( 𝑡  =  𝑠  →  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) )  =  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) | 
						
							| 243 | 238 242 | oveq12d | ⊢ ( 𝑡  =  𝑠  →  ( ( - 1 ↑ ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) ) )  =  ( ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 244 | 243 | cbvsumv | ⊢ Σ 𝑡  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) | 
						
							| 245 | 54 | a1i | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  - 1  ∈  ℂ ) | 
						
							| 246 |  | elpwi | ⊢ ( 𝑠  ∈  𝒫  𝑦  →  𝑠  ⊆  𝑦 ) | 
						
							| 247 |  | ssfi | ⊢ ( ( 𝑦  ∈  Fin  ∧  𝑠  ⊆  𝑦 )  →  𝑠  ∈  Fin ) | 
						
							| 248 | 142 246 247 | syl2an | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  𝑠  ∈  Fin ) | 
						
							| 249 | 248 152 | syl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ♯ ‘ 𝑠 )  ∈  ℕ0 ) | 
						
							| 250 | 245 249 | expp1d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - 1 ↑ ( ( ♯ ‘ 𝑠 )  +  1 ) )  =  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  - 1 ) ) | 
						
							| 251 | 246 | adantl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  𝑠  ⊆  𝑦 ) | 
						
							| 252 |  | simpllr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ¬  𝑧  ∈  𝑦 ) | 
						
							| 253 | 251 252 | ssneldd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ¬  𝑧  ∈  𝑠 ) | 
						
							| 254 |  | hashunsng | ⊢ ( 𝑧  ∈  V  →  ( ( 𝑠  ∈  Fin  ∧  ¬  𝑧  ∈  𝑠 )  →  ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) )  =  ( ( ♯ ‘ 𝑠 )  +  1 ) ) ) | 
						
							| 255 | 254 | elv | ⊢ ( ( 𝑠  ∈  Fin  ∧  ¬  𝑧  ∈  𝑠 )  →  ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) )  =  ( ( ♯ ‘ 𝑠 )  +  1 ) ) | 
						
							| 256 | 248 253 255 | syl2anc | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) )  =  ( ( ♯ ‘ 𝑠 )  +  1 ) ) | 
						
							| 257 | 256 | oveq2d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  =  ( - 1 ↑ ( ( ♯ ‘ 𝑠 )  +  1 ) ) ) | 
						
							| 258 | 137 | sseli | ⊢ ( 𝑠  ∈  𝒫  𝑦  →  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 259 | 258 154 | sylan2 | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ∈  ℂ ) | 
						
							| 260 | 245 259 | mulcomd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - 1  ·  ( - 1 ↑ ( ♯ ‘ 𝑠 ) ) )  =  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  - 1 ) ) | 
						
							| 261 | 250 257 260 | 3eqtr4d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  =  ( - 1  ·  ( - 1 ↑ ( ♯ ‘ 𝑠 ) ) ) ) | 
						
							| 262 | 259 | mulm1d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - 1  ·  ( - 1 ↑ ( ♯ ‘ 𝑠 ) ) )  =  - ( - 1 ↑ ( ♯ ‘ 𝑠 ) ) ) | 
						
							| 263 | 261 262 | eqtrd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  =  - ( - 1 ↑ ( ♯ ‘ 𝑠 ) ) ) | 
						
							| 264 | 263 | oveq1d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  =  ( - ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 265 |  | inss1 | ⊢ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) )  ⊆  𝑥 | 
						
							| 266 |  | ssfi | ⊢ ( ( 𝑥  ∈  Fin  ∧  ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) )  ⊆  𝑥 )  →  ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) )  ∈  Fin ) | 
						
							| 267 | 155 265 266 | sylancl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) )  ∈  Fin ) | 
						
							| 268 |  | hashcl | ⊢ ( ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) )  ∈  Fin  →  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) )  ∈  ℕ0 ) | 
						
							| 269 | 267 268 | syl | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) )  ∈  ℕ0 ) | 
						
							| 270 | 269 | nn0cnd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) )  ∈  ℂ ) | 
						
							| 271 | 258 270 | sylan2 | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) )  ∈  ℂ ) | 
						
							| 272 | 259 271 | mulneg1d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( - ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  =  - ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 273 | 264 272 | eqtrd | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  =  - ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 274 | 273 | sumeq2dv | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ ( 𝑠  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 - ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 275 | 244 274 | eqtrid | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑡  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ ( 𝑡  ∪  { 𝑧 } ) ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑡  ∩  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 - ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 276 | 154 270 | mulcld | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  ∈  ℂ ) | 
						
							| 277 | 258 276 | sylan2 | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  ∈  ℂ ) | 
						
							| 278 | 174 277 | fsumneg | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  𝒫  𝑦 - ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  =  - Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 279 | 235 275 278 | 3eqtrd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  =  - Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) | 
						
							| 280 | 279 | oveq2d | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  +  Σ 𝑠  ∈  ( 𝒫  ( 𝑦  ∪  { 𝑧 } )  ∖  𝒫  𝑦 ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) )  =  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  +  - Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 281 | 137 | a1i | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  𝒫  𝑦  ⊆  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 282 | 281 | sselda | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ) | 
						
							| 283 | 282 162 | syldan | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  ∈  ℂ ) | 
						
							| 284 | 174 283 | fsumcl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  ∈  ℂ ) | 
						
							| 285 | 282 276 | syldan | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  𝑠  ∈  𝒫  𝑦 )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  ∈  ℂ ) | 
						
							| 286 | 174 285 | fsumcl | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) )  ∈  ℂ ) | 
						
							| 287 | 284 286 | negsubd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  +  - Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) )  =  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  −  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 288 | 163 280 287 | 3eqtrd | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  =  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  −  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 289 | 288 | adantr | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  =  ( Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) )  −  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ( ∩  𝑠  ∩  𝑧 ) ) ) ) ) ) | 
						
							| 290 | 101 133 289 | 3eqtr4d | ⊢ ( ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  ∧  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) )  →  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 291 | 290 | ex | ⊢ ( ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  ∧  𝑥  ∈  Fin )  →  ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  →  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 292 | 291 | ralrimdva | ⊢ ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  →  ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  →  ∀ 𝑥  ∈  Fin ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 293 |  | ineq1 | ⊢ ( 𝑏  =  𝑥  →  ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) )  =  ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) | 
						
							| 294 | 293 | fveq2d | ⊢ ( 𝑏  =  𝑥  →  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) )  =  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) ) | 
						
							| 295 | 66 294 | oveq12d | ⊢ ( 𝑏  =  𝑥  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) ) ) | 
						
							| 296 |  | ineq1 | ⊢ ( 𝑏  =  𝑥  →  ( 𝑏  ∩  ∩  𝑠 )  =  ( 𝑥  ∩  ∩  𝑠 ) ) | 
						
							| 297 | 296 | fveq2d | ⊢ ( 𝑏  =  𝑥  →  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) )  =  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) | 
						
							| 298 | 297 | oveq2d | ⊢ ( 𝑏  =  𝑥  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 299 | 298 | sumeq2sdv | ⊢ ( 𝑏  =  𝑥  →  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 300 | 295 299 | eqeq12d | ⊢ ( 𝑏  =  𝑥  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 301 | 300 | cbvralvw | ⊢ ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ∀ 𝑥  ∈  Fin ( ( ♯ ‘ 𝑥 )  −  ( ♯ ‘ ( 𝑥  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑥  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 302 | 292 301 | imbitrrdi | ⊢ ( ( 𝑦  ∈  Fin  ∧  ¬  𝑧  ∈  𝑦 )  →  ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝑦 ) ) )  =  Σ 𝑠  ∈  𝒫  𝑦 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  →  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ( ∪  𝑦  ∪  𝑧 ) ) ) )  =  Σ 𝑠  ∈  𝒫  ( 𝑦  ∪  { 𝑧 } ) ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 303 | 16 24 37 45 65 302 | findcard2s | ⊢ ( 𝐴  ∈  Fin  →  ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 304 |  | fveq2 | ⊢ ( 𝑏  =  𝐵  →  ( ♯ ‘ 𝑏 )  =  ( ♯ ‘ 𝐵 ) ) | 
						
							| 305 |  | ineq1 | ⊢ ( 𝑏  =  𝐵  →  ( 𝑏  ∩  ∪  𝐴 )  =  ( 𝐵  ∩  ∪  𝐴 ) ) | 
						
							| 306 | 305 | fveq2d | ⊢ ( 𝑏  =  𝐵  →  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) )  =  ( ♯ ‘ ( 𝐵  ∩  ∪  𝐴 ) ) ) | 
						
							| 307 | 304 306 | oveq12d | ⊢ ( 𝑏  =  𝐵  →  ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) )  =  ( ( ♯ ‘ 𝐵 )  −  ( ♯ ‘ ( 𝐵  ∩  ∪  𝐴 ) ) ) ) | 
						
							| 308 |  | simpl | ⊢ ( ( 𝑏  =  𝐵  ∧  𝑠  ∈  𝒫  𝐴 )  →  𝑏  =  𝐵 ) | 
						
							| 309 | 308 | ineq1d | ⊢ ( ( 𝑏  =  𝐵  ∧  𝑠  ∈  𝒫  𝐴 )  →  ( 𝑏  ∩  ∩  𝑠 )  =  ( 𝐵  ∩  ∩  𝑠 ) ) | 
						
							| 310 | 309 | fveq2d | ⊢ ( ( 𝑏  =  𝐵  ∧  𝑠  ∈  𝒫  𝐴 )  →  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) )  =  ( ♯ ‘ ( 𝐵  ∩  ∩  𝑠 ) ) ) | 
						
							| 311 | 310 | oveq2d | ⊢ ( ( 𝑏  =  𝐵  ∧  𝑠  ∈  𝒫  𝐴 )  →  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝐵  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 312 | 311 | sumeq2dv | ⊢ ( 𝑏  =  𝐵  →  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝐵  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 313 | 307 312 | eqeq12d | ⊢ ( 𝑏  =  𝐵  →  ( ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ↔  ( ( ♯ ‘ 𝐵 )  −  ( ♯ ‘ ( 𝐵  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝐵  ∩  ∩  𝑠 ) ) ) ) ) | 
						
							| 314 | 313 | rspccva | ⊢ ( ( ∀ 𝑏  ∈  Fin ( ( ♯ ‘ 𝑏 )  −  ( ♯ ‘ ( 𝑏  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝑏  ∩  ∩  𝑠 ) ) )  ∧  𝐵  ∈  Fin )  →  ( ( ♯ ‘ 𝐵 )  −  ( ♯ ‘ ( 𝐵  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝐵  ∩  ∩  𝑠 ) ) ) ) | 
						
							| 315 | 303 314 | sylan | ⊢ ( ( 𝐴  ∈  Fin  ∧  𝐵  ∈  Fin )  →  ( ( ♯ ‘ 𝐵 )  −  ( ♯ ‘ ( 𝐵  ∩  ∪  𝐴 ) ) )  =  Σ 𝑠  ∈  𝒫  𝐴 ( ( - 1 ↑ ( ♯ ‘ 𝑠 ) )  ·  ( ♯ ‘ ( 𝐵  ∩  ∩  𝑠 ) ) ) ) |