| Step | Hyp | Ref | Expression | 
						
							| 1 |  | coe1tm.z | ⊢  0   =  ( 0g ‘ 𝑅 ) | 
						
							| 2 |  | coe1tm.k | ⊢ 𝐾  =  ( Base ‘ 𝑅 ) | 
						
							| 3 |  | coe1tm.p | ⊢ 𝑃  =  ( Poly1 ‘ 𝑅 ) | 
						
							| 4 |  | coe1tm.x | ⊢ 𝑋  =  ( var1 ‘ 𝑅 ) | 
						
							| 5 |  | coe1tm.m | ⊢  ·   =  (  ·𝑠  ‘ 𝑃 ) | 
						
							| 6 |  | coe1tm.n | ⊢ 𝑁  =  ( mulGrp ‘ 𝑃 ) | 
						
							| 7 |  | coe1tm.e | ⊢  ↑   =  ( .g ‘ 𝑁 ) | 
						
							| 8 |  | coe1tmmul.b | ⊢ 𝐵  =  ( Base ‘ 𝑃 ) | 
						
							| 9 |  | coe1tmmul.t | ⊢  ∙   =  ( .r ‘ 𝑃 ) | 
						
							| 10 |  | coe1tmmul.u | ⊢  ×   =  ( .r ‘ 𝑅 ) | 
						
							| 11 |  | coe1tmmul.a | ⊢ ( 𝜑  →  𝐴  ∈  𝐵 ) | 
						
							| 12 |  | coe1tmmul.r | ⊢ ( 𝜑  →  𝑅  ∈  Ring ) | 
						
							| 13 |  | coe1tmmul.c | ⊢ ( 𝜑  →  𝐶  ∈  𝐾 ) | 
						
							| 14 |  | coe1tmmul.d | ⊢ ( 𝜑  →  𝐷  ∈  ℕ0 ) | 
						
							| 15 | 2 3 4 5 6 7 8 | ply1tmcl | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝐶  ∈  𝐾  ∧  𝐷  ∈  ℕ0 )  →  ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) )  ∈  𝐵 ) | 
						
							| 16 | 12 13 14 15 | syl3anc | ⊢ ( 𝜑  →  ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) )  ∈  𝐵 ) | 
						
							| 17 | 3 9 10 8 | coe1mul | ⊢ ( ( 𝑅  ∈  Ring  ∧  ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) )  ∈  𝐵  ∧  𝐴  ∈  𝐵 )  →  ( coe1 ‘ ( ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) )  ∙  𝐴 ) )  =  ( 𝑥  ∈  ℕ0  ↦  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) ) ) ) | 
						
							| 18 | 12 16 11 17 | syl3anc | ⊢ ( 𝜑  →  ( coe1 ‘ ( ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) )  ∙  𝐴 ) )  =  ( 𝑥  ∈  ℕ0  ↦  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) ) ) ) | 
						
							| 19 |  | eqeq2 | ⊢ ( ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) )  =  if ( 𝐷  ≤  𝑥 ,  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ,   0  )  →  ( ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) )  ↔  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =  if ( 𝐷  ≤  𝑥 ,  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ,   0  ) ) ) | 
						
							| 20 |  | eqeq2 | ⊢ (  0   =  if ( 𝐷  ≤  𝑥 ,  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ,   0  )  →  ( ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =   0   ↔  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =  if ( 𝐷  ≤  𝑥 ,  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ,   0  ) ) ) | 
						
							| 21 | 12 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  𝑅  ∈  Ring ) | 
						
							| 22 |  | ringmnd | ⊢ ( 𝑅  ∈  Ring  →  𝑅  ∈  Mnd ) | 
						
							| 23 | 21 22 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  𝑅  ∈  Mnd ) | 
						
							| 24 |  | ovexd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( 0 ... 𝑥 )  ∈  V ) | 
						
							| 25 | 14 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  𝐷  ∈  ℕ0 ) | 
						
							| 26 |  | simpr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  𝐷  ≤  𝑥 ) | 
						
							| 27 |  | fznn0 | ⊢ ( 𝑥  ∈  ℕ0  →  ( 𝐷  ∈  ( 0 ... 𝑥 )  ↔  ( 𝐷  ∈  ℕ0  ∧  𝐷  ≤  𝑥 ) ) ) | 
						
							| 28 | 27 | ad2antlr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( 𝐷  ∈  ( 0 ... 𝑥 )  ↔  ( 𝐷  ∈  ℕ0  ∧  𝐷  ≤  𝑥 ) ) ) | 
						
							| 29 | 25 26 28 | mpbir2and | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  𝐷  ∈  ( 0 ... 𝑥 ) ) | 
						
							| 30 | 12 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  𝑅  ∈  Ring ) | 
						
							| 31 |  | eqid | ⊢ ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) )  =  ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) | 
						
							| 32 | 31 8 3 2 | coe1f | ⊢ ( ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) )  ∈  𝐵  →  ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) : ℕ0 ⟶ 𝐾 ) | 
						
							| 33 | 16 32 | syl | ⊢ ( 𝜑  →  ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) : ℕ0 ⟶ 𝐾 ) | 
						
							| 34 | 33 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  →  ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) : ℕ0 ⟶ 𝐾 ) | 
						
							| 35 |  | elfznn0 | ⊢ ( 𝑦  ∈  ( 0 ... 𝑥 )  →  𝑦  ∈  ℕ0 ) | 
						
							| 36 |  | ffvelcdm | ⊢ ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) : ℕ0 ⟶ 𝐾  ∧  𝑦  ∈  ℕ0 )  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ∈  𝐾 ) | 
						
							| 37 | 34 35 36 | syl2an | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ∈  𝐾 ) | 
						
							| 38 |  | eqid | ⊢ ( coe1 ‘ 𝐴 )  =  ( coe1 ‘ 𝐴 ) | 
						
							| 39 | 38 8 3 2 | coe1f | ⊢ ( 𝐴  ∈  𝐵  →  ( coe1 ‘ 𝐴 ) : ℕ0 ⟶ 𝐾 ) | 
						
							| 40 | 11 39 | syl | ⊢ ( 𝜑  →  ( coe1 ‘ 𝐴 ) : ℕ0 ⟶ 𝐾 ) | 
						
							| 41 | 40 | adantr | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  →  ( coe1 ‘ 𝐴 ) : ℕ0 ⟶ 𝐾 ) | 
						
							| 42 |  | fznn0sub | ⊢ ( 𝑦  ∈  ( 0 ... 𝑥 )  →  ( 𝑥  −  𝑦 )  ∈  ℕ0 ) | 
						
							| 43 |  | ffvelcdm | ⊢ ( ( ( coe1 ‘ 𝐴 ) : ℕ0 ⟶ 𝐾  ∧  ( 𝑥  −  𝑦 )  ∈  ℕ0 )  →  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) )  ∈  𝐾 ) | 
						
							| 44 | 41 42 43 | syl2an | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) )  ∈  𝐾 ) | 
						
							| 45 | 2 10 | ringcl | ⊢ ( ( 𝑅  ∈  Ring  ∧  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ∈  𝐾  ∧  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) )  ∈  𝐾 )  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  ∈  𝐾 ) | 
						
							| 46 | 30 37 44 45 | syl3anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  ∈  𝐾 ) | 
						
							| 47 | 46 | fmpttd | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  →  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) : ( 0 ... 𝑥 ) ⟶ 𝐾 ) | 
						
							| 48 | 47 | adantr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) : ( 0 ... 𝑥 ) ⟶ 𝐾 ) | 
						
							| 49 | 12 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  𝑅  ∈  Ring ) | 
						
							| 50 | 13 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  𝐶  ∈  𝐾 ) | 
						
							| 51 | 14 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  𝐷  ∈  ℕ0 ) | 
						
							| 52 |  | eldifi | ⊢ ( 𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } )  →  𝑦  ∈  ( 0 ... 𝑥 ) ) | 
						
							| 53 | 52 35 | syl | ⊢ ( 𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } )  →  𝑦  ∈  ℕ0 ) | 
						
							| 54 | 53 | adantl | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  𝑦  ∈  ℕ0 ) | 
						
							| 55 |  | eldifsni | ⊢ ( 𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } )  →  𝑦  ≠  𝐷 ) | 
						
							| 56 | 55 | necomd | ⊢ ( 𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } )  →  𝐷  ≠  𝑦 ) | 
						
							| 57 | 56 | adantl | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  𝐷  ≠  𝑦 ) | 
						
							| 58 | 1 2 3 4 5 6 7 49 50 51 54 57 | coe1tmfv2 | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  =   0  ) | 
						
							| 59 | 58 | oveq1d | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =  (  0   ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) | 
						
							| 60 | 2 10 1 | ringlz | ⊢ ( ( 𝑅  ∈  Ring  ∧  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) )  ∈  𝐾 )  →  (  0   ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =   0  ) | 
						
							| 61 | 30 44 60 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  (  0   ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =   0  ) | 
						
							| 62 | 52 61 | sylan2 | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  (  0   ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =   0  ) | 
						
							| 63 | 62 | adantlr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  (  0   ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =   0  ) | 
						
							| 64 | 59 63 | eqtrd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( ( 0 ... 𝑥 )  ∖  { 𝐷 } ) )  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =   0  ) | 
						
							| 65 | 64 24 | suppss2 | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) )  supp   0  )  ⊆  { 𝐷 } ) | 
						
							| 66 | 2 1 23 24 29 48 65 | gsumpt | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =  ( ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) ‘ 𝐷 ) ) | 
						
							| 67 |  | fveq2 | ⊢ ( 𝑦  =  𝐷  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  =  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 ) ) | 
						
							| 68 |  | oveq2 | ⊢ ( 𝑦  =  𝐷  →  ( 𝑥  −  𝑦 )  =  ( 𝑥  −  𝐷 ) ) | 
						
							| 69 | 68 | fveq2d | ⊢ ( 𝑦  =  𝐷  →  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) )  =  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) | 
						
							| 70 | 67 69 | oveq12d | ⊢ ( 𝑦  =  𝐷  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ) | 
						
							| 71 |  | eqid | ⊢ ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) )  =  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) | 
						
							| 72 |  | ovex | ⊢ ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) )  ∈  V | 
						
							| 73 | 70 71 72 | fvmpt | ⊢ ( 𝐷  ∈  ( 0 ... 𝑥 )  →  ( ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) ‘ 𝐷 )  =  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ) | 
						
							| 74 | 29 73 | syl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) ‘ 𝐷 )  =  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ) | 
						
							| 75 | 1 2 3 4 5 6 7 | coe1tmfv1 | ⊢ ( ( 𝑅  ∈  Ring  ∧  𝐶  ∈  𝐾  ∧  𝐷  ∈  ℕ0 )  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  =  𝐶 ) | 
						
							| 76 | 12 13 14 75 | syl3anc | ⊢ ( 𝜑  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  =  𝐶 ) | 
						
							| 77 | 76 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  =  𝐶 ) | 
						
							| 78 | 77 | oveq1d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝐷 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) )  =  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ) | 
						
							| 79 | 74 78 | eqtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) ‘ 𝐷 )  =  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ) | 
						
							| 80 | 66 79 | eqtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝐷  ≤  𝑥 )  →  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ) | 
						
							| 81 | 12 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  𝑅  ∈  Ring ) | 
						
							| 82 | 13 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  𝐶  ∈  𝐾 ) | 
						
							| 83 | 14 | ad3antrrr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  𝐷  ∈  ℕ0 ) | 
						
							| 84 | 35 | adantl | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  𝑦  ∈  ℕ0 ) | 
						
							| 85 |  | elfzle2 | ⊢ ( 𝑦  ∈  ( 0 ... 𝑥 )  →  𝑦  ≤  𝑥 ) | 
						
							| 86 | 85 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  𝑦  ≤  𝑥 ) | 
						
							| 87 |  | breq1 | ⊢ ( 𝐷  =  𝑦  →  ( 𝐷  ≤  𝑥  ↔  𝑦  ≤  𝑥 ) ) | 
						
							| 88 | 86 87 | syl5ibrcom | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( 𝐷  =  𝑦  →  𝐷  ≤  𝑥 ) ) | 
						
							| 89 | 88 | necon3bd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( ¬  𝐷  ≤  𝑥  →  𝐷  ≠  𝑦 ) ) | 
						
							| 90 | 89 | imp | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  ∧  ¬  𝐷  ≤  𝑥 )  →  𝐷  ≠  𝑦 ) | 
						
							| 91 | 90 | an32s | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  𝐷  ≠  𝑦 ) | 
						
							| 92 | 1 2 3 4 5 6 7 81 82 83 84 91 | coe1tmfv2 | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  =   0  ) | 
						
							| 93 | 92 | oveq1d | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =  (  0   ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) | 
						
							| 94 | 61 | adantlr | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  (  0   ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =   0  ) | 
						
							| 95 | 93 94 | eqtrd | ⊢ ( ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  ∧  𝑦  ∈  ( 0 ... 𝑥 ) )  →  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) )  =   0  ) | 
						
							| 96 | 95 | mpteq2dva | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  →  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) )  =  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦   0  ) ) | 
						
							| 97 | 96 | oveq2d | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  →  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦   0  ) ) ) | 
						
							| 98 | 12 22 | syl | ⊢ ( 𝜑  →  𝑅  ∈  Mnd ) | 
						
							| 99 | 98 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  →  𝑅  ∈  Mnd ) | 
						
							| 100 |  | ovexd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  →  ( 0 ... 𝑥 )  ∈  V ) | 
						
							| 101 | 1 | gsumz | ⊢ ( ( 𝑅  ∈  Mnd  ∧  ( 0 ... 𝑥 )  ∈  V )  →  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦   0  ) )  =   0  ) | 
						
							| 102 | 99 100 101 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  →  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦   0  ) )  =   0  ) | 
						
							| 103 | 97 102 | eqtrd | ⊢ ( ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  ∧  ¬  𝐷  ≤  𝑥 )  →  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =   0  ) | 
						
							| 104 | 19 20 80 103 | ifbothda | ⊢ ( ( 𝜑  ∧  𝑥  ∈  ℕ0 )  →  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) )  =  if ( 𝐷  ≤  𝑥 ,  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ,   0  ) ) | 
						
							| 105 | 104 | mpteq2dva | ⊢ ( 𝜑  →  ( 𝑥  ∈  ℕ0  ↦  ( 𝑅  Σg  ( 𝑦  ∈  ( 0 ... 𝑥 )  ↦  ( ( ( coe1 ‘ ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) ) ) ‘ 𝑦 )  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝑦 ) ) ) ) ) )  =  ( 𝑥  ∈  ℕ0  ↦  if ( 𝐷  ≤  𝑥 ,  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ,   0  ) ) ) | 
						
							| 106 | 18 105 | eqtrd | ⊢ ( 𝜑  →  ( coe1 ‘ ( ( 𝐶  ·  ( 𝐷  ↑  𝑋 ) )  ∙  𝐴 ) )  =  ( 𝑥  ∈  ℕ0  ↦  if ( 𝐷  ≤  𝑥 ,  ( 𝐶  ×  ( ( coe1 ‘ 𝐴 ) ‘ ( 𝑥  −  𝐷 ) ) ) ,   0  ) ) ) |