| Step | Hyp | Ref | Expression | 
						
							| 1 |  | psdffval.s | ⊢ 𝑆  =  ( 𝐼  mPwSer  𝑅 ) | 
						
							| 2 |  | psdffval.b | ⊢ 𝐵  =  ( Base ‘ 𝑆 ) | 
						
							| 3 |  | psdffval.d | ⊢ 𝐷  =  { ℎ  ∈  ( ℕ0  ↑m  𝐼 )  ∣  ( ◡ ℎ  “  ℕ )  ∈  Fin } | 
						
							| 4 |  | psdffval.i | ⊢ ( 𝜑  →  𝐼  ∈  𝑉 ) | 
						
							| 5 |  | psdffval.r | ⊢ ( 𝜑  →  𝑅  ∈  𝑊 ) | 
						
							| 6 |  | psdfval.x | ⊢ ( 𝜑  →  𝑋  ∈  𝐼 ) | 
						
							| 7 | 1 2 3 4 5 | psdffval | ⊢ ( 𝜑  →  ( 𝐼  mPSDer  𝑅 )  =  ( 𝑥  ∈  𝐼  ↦  ( 𝑓  ∈  𝐵  ↦  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑥 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) ) ) ) ) ) ) ) ) | 
						
							| 8 |  | fveq2 | ⊢ ( 𝑥  =  𝑋  →  ( 𝑘 ‘ 𝑥 )  =  ( 𝑘 ‘ 𝑋 ) ) | 
						
							| 9 | 8 | oveq1d | ⊢ ( 𝑥  =  𝑋  →  ( ( 𝑘 ‘ 𝑥 )  +  1 )  =  ( ( 𝑘 ‘ 𝑋 )  +  1 ) ) | 
						
							| 10 |  | eqeq2 | ⊢ ( 𝑥  =  𝑋  →  ( 𝑦  =  𝑥  ↔  𝑦  =  𝑋 ) ) | 
						
							| 11 | 10 | ifbid | ⊢ ( 𝑥  =  𝑋  →  if ( 𝑦  =  𝑥 ,  1 ,  0 )  =  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) | 
						
							| 12 | 11 | mpteq2dv | ⊢ ( 𝑥  =  𝑋  →  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) )  =  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) | 
						
							| 13 | 12 | oveq2d | ⊢ ( 𝑥  =  𝑋  →  ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) ) )  =  ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) | 
						
							| 14 | 13 | fveq2d | ⊢ ( 𝑥  =  𝑋  →  ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) ) ) )  =  ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) ) | 
						
							| 15 | 9 14 | oveq12d | ⊢ ( 𝑥  =  𝑋  →  ( ( ( 𝑘 ‘ 𝑥 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) ) ) ) )  =  ( ( ( 𝑘 ‘ 𝑋 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) ) ) | 
						
							| 16 | 15 | mpteq2dv | ⊢ ( 𝑥  =  𝑋  →  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑥 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) ) ) ) ) )  =  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑋 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) ) ) ) | 
						
							| 17 | 16 | mpteq2dv | ⊢ ( 𝑥  =  𝑋  →  ( 𝑓  ∈  𝐵  ↦  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑥 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) ) ) ) ) ) )  =  ( 𝑓  ∈  𝐵  ↦  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑋 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) ) ) ) ) | 
						
							| 18 | 17 | adantl | ⊢ ( ( 𝜑  ∧  𝑥  =  𝑋 )  →  ( 𝑓  ∈  𝐵  ↦  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑥 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑥 ,  1 ,  0 ) ) ) ) ) ) )  =  ( 𝑓  ∈  𝐵  ↦  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑋 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) ) ) ) ) | 
						
							| 19 | 2 | fvexi | ⊢ 𝐵  ∈  V | 
						
							| 20 | 19 | a1i | ⊢ ( 𝜑  →  𝐵  ∈  V ) | 
						
							| 21 | 20 | mptexd | ⊢ ( 𝜑  →  ( 𝑓  ∈  𝐵  ↦  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑋 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) ) ) )  ∈  V ) | 
						
							| 22 | 7 18 6 21 | fvmptd | ⊢ ( 𝜑  →  ( ( 𝐼  mPSDer  𝑅 ) ‘ 𝑋 )  =  ( 𝑓  ∈  𝐵  ↦  ( 𝑘  ∈  𝐷  ↦  ( ( ( 𝑘 ‘ 𝑋 )  +  1 ) ( .g ‘ 𝑅 ) ( 𝑓 ‘ ( 𝑘  ∘f   +  ( 𝑦  ∈  𝐼  ↦  if ( 𝑦  =  𝑋 ,  1 ,  0 ) ) ) ) ) ) ) ) |