| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ofcccat.1 | ⊢ ( 𝜑  →  𝐹  ∈  Word  𝑆 ) | 
						
							| 2 |  | ofcccat.2 | ⊢ ( 𝜑  →  𝐺  ∈  Word  𝑆 ) | 
						
							| 3 |  | ofcccat.3 | ⊢ ( 𝜑  →  𝐾  ∈  𝑇 ) | 
						
							| 4 |  | fconst6g | ⊢ ( 𝐾  ∈  𝑇  →  ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) : ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ⟶ 𝑇 ) | 
						
							| 5 |  | iswrdi | ⊢ ( ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) : ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ⟶ 𝑇  →  ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  ∈  Word  𝑇 ) | 
						
							| 6 | 3 4 5 | 3syl | ⊢ ( 𝜑  →  ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  ∈  Word  𝑇 ) | 
						
							| 7 |  | fconst6g | ⊢ ( 𝐾  ∈  𝑇  →  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) : ( 0 ..^ ( ♯ ‘ 𝐺 ) ) ⟶ 𝑇 ) | 
						
							| 8 |  | iswrdi | ⊢ ( ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) : ( 0 ..^ ( ♯ ‘ 𝐺 ) ) ⟶ 𝑇  →  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } )  ∈  Word  𝑇 ) | 
						
							| 9 | 3 7 8 | 3syl | ⊢ ( 𝜑  →  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } )  ∈  Word  𝑇 ) | 
						
							| 10 |  | fzofi | ⊢ ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ∈  Fin | 
						
							| 11 |  | snfi | ⊢ { 𝐾 }  ∈  Fin | 
						
							| 12 |  | hashxp | ⊢ ( ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ∈  Fin  ∧  { 𝐾 }  ∈  Fin )  →  ( ♯ ‘ ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) )  =  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) ) ) | 
						
							| 13 | 10 11 12 | mp2an | ⊢ ( ♯ ‘ ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) )  =  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) ) | 
						
							| 14 |  | lencl | ⊢ ( 𝐹  ∈  Word  𝑆  →  ( ♯ ‘ 𝐹 )  ∈  ℕ0 ) | 
						
							| 15 |  | hashfzo0 | ⊢ ( ( ♯ ‘ 𝐹 )  ∈  ℕ0  →  ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 16 | 1 14 15 | 3syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 17 |  | hashsng | ⊢ ( 𝐾  ∈  𝑇  →  ( ♯ ‘ { 𝐾 } )  =  1 ) | 
						
							| 18 | 3 17 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ { 𝐾 } )  =  1 ) | 
						
							| 19 | 16 18 | oveq12d | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) )  =  ( ( ♯ ‘ 𝐹 )  ·  1 ) ) | 
						
							| 20 | 1 14 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐹 )  ∈  ℕ0 ) | 
						
							| 21 | 20 | nn0cnd | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐹 )  ∈  ℂ ) | 
						
							| 22 | 21 | mulridd | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐹 )  ·  1 )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 23 | 19 22 | eqtrd | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐹 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) )  =  ( ♯ ‘ 𝐹 ) ) | 
						
							| 24 | 13 23 | eqtr2id | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐹 )  =  ( ♯ ‘ ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) ) ) | 
						
							| 25 |  | fzofi | ⊢ ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ∈  Fin | 
						
							| 26 |  | hashxp | ⊢ ( ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ∈  Fin  ∧  { 𝐾 }  ∈  Fin )  →  ( ♯ ‘ ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) )  =  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐺 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) ) ) | 
						
							| 27 | 25 11 26 | mp2an | ⊢ ( ♯ ‘ ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) )  =  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐺 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) ) | 
						
							| 28 |  | lencl | ⊢ ( 𝐺  ∈  Word  𝑆  →  ( ♯ ‘ 𝐺 )  ∈  ℕ0 ) | 
						
							| 29 |  | hashfzo0 | ⊢ ( ( ♯ ‘ 𝐺 )  ∈  ℕ0  →  ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐺 ) ) )  =  ( ♯ ‘ 𝐺 ) ) | 
						
							| 30 | 2 28 29 | 3syl | ⊢ ( 𝜑  →  ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐺 ) ) )  =  ( ♯ ‘ 𝐺 ) ) | 
						
							| 31 | 30 18 | oveq12d | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐺 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) )  =  ( ( ♯ ‘ 𝐺 )  ·  1 ) ) | 
						
							| 32 | 2 28 | syl | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐺 )  ∈  ℕ0 ) | 
						
							| 33 | 32 | nn0cnd | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐺 )  ∈  ℂ ) | 
						
							| 34 | 33 | mulridd | ⊢ ( 𝜑  →  ( ( ♯ ‘ 𝐺 )  ·  1 )  =  ( ♯ ‘ 𝐺 ) ) | 
						
							| 35 | 31 34 | eqtrd | ⊢ ( 𝜑  →  ( ( ♯ ‘ ( 0 ..^ ( ♯ ‘ 𝐺 ) ) )  ·  ( ♯ ‘ { 𝐾 } ) )  =  ( ♯ ‘ 𝐺 ) ) | 
						
							| 36 | 27 35 | eqtr2id | ⊢ ( 𝜑  →  ( ♯ ‘ 𝐺 )  =  ( ♯ ‘ ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) ) | 
						
							| 37 | 1 2 6 9 24 36 | ofccat | ⊢ ( 𝜑  →  ( ( 𝐹  ++  𝐺 )  ∘f  𝑅 ( ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  ++  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) )  =  ( ( 𝐹  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) )  ++  ( 𝐺  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) ) ) | 
						
							| 38 |  | ccatcl | ⊢ ( ( 𝐹  ∈  Word  𝑆  ∧  𝐺  ∈  Word  𝑆 )  →  ( 𝐹  ++  𝐺 )  ∈  Word  𝑆 ) | 
						
							| 39 | 1 2 38 | syl2anc | ⊢ ( 𝜑  →  ( 𝐹  ++  𝐺 )  ∈  Word  𝑆 ) | 
						
							| 40 |  | wrdf | ⊢ ( ( 𝐹  ++  𝐺 )  ∈  Word  𝑆  →  ( 𝐹  ++  𝐺 ) : ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) ) ⟶ 𝑆 ) | 
						
							| 41 | 39 40 | syl | ⊢ ( 𝜑  →  ( 𝐹  ++  𝐺 ) : ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) ) ⟶ 𝑆 ) | 
						
							| 42 |  | ovexd | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) )  ∈  V ) | 
						
							| 43 | 41 42 3 | ofcof | ⊢ ( 𝜑  →  ( ( 𝐹  ++  𝐺 )  ∘f/c  𝑅 𝐾 )  =  ( ( 𝐹  ++  𝐺 )  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) )  ×  { 𝐾 } ) ) ) | 
						
							| 44 |  | eqid | ⊢ ( ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 𝐺 ) ) )  ×  { 𝐾 } )  =  ( ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 𝐺 ) ) )  ×  { 𝐾 } ) | 
						
							| 45 |  | ccatlen | ⊢ ( ( 𝐹  ∈  Word  𝑆  ∧  𝐺  ∈  Word  𝑆 )  →  ( ♯ ‘ ( 𝐹  ++  𝐺 ) )  =  ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 𝐺 ) ) ) | 
						
							| 46 | 1 2 45 | syl2anc | ⊢ ( 𝜑  →  ( ♯ ‘ ( 𝐹  ++  𝐺 ) )  =  ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 𝐺 ) ) ) | 
						
							| 47 | 46 | oveq2d | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) )  =  ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 𝐺 ) ) ) ) | 
						
							| 48 | 47 | xpeq1d | ⊢ ( 𝜑  →  ( ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) )  ×  { 𝐾 } )  =  ( ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 𝐺 ) ) )  ×  { 𝐾 } ) ) | 
						
							| 49 |  | eqid | ⊢ ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  =  ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) | 
						
							| 50 |  | eqid | ⊢ ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } )  =  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) | 
						
							| 51 | 49 50 44 3 20 32 | ccatmulgnn0dir | ⊢ ( 𝜑  →  ( ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  ++  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) )  =  ( ( 0 ..^ ( ( ♯ ‘ 𝐹 )  +  ( ♯ ‘ 𝐺 ) ) )  ×  { 𝐾 } ) ) | 
						
							| 52 | 44 48 51 | 3eqtr4a | ⊢ ( 𝜑  →  ( ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) )  ×  { 𝐾 } )  =  ( ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  ++  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) ) | 
						
							| 53 | 52 | oveq2d | ⊢ ( 𝜑  →  ( ( 𝐹  ++  𝐺 )  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ ( 𝐹  ++  𝐺 ) ) )  ×  { 𝐾 } ) )  =  ( ( 𝐹  ++  𝐺 )  ∘f  𝑅 ( ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  ++  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) ) ) | 
						
							| 54 | 43 53 | eqtrd | ⊢ ( 𝜑  →  ( ( 𝐹  ++  𝐺 )  ∘f/c  𝑅 𝐾 )  =  ( ( 𝐹  ++  𝐺 )  ∘f  𝑅 ( ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } )  ++  ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) ) ) | 
						
							| 55 |  | wrdf | ⊢ ( 𝐹  ∈  Word  𝑆  →  𝐹 : ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ⟶ 𝑆 ) | 
						
							| 56 | 1 55 | syl | ⊢ ( 𝜑  →  𝐹 : ( 0 ..^ ( ♯ ‘ 𝐹 ) ) ⟶ 𝑆 ) | 
						
							| 57 |  | ovexd | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ∈  V ) | 
						
							| 58 | 56 57 3 | ofcof | ⊢ ( 𝜑  →  ( 𝐹  ∘f/c  𝑅 𝐾 )  =  ( 𝐹  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) ) ) | 
						
							| 59 |  | wrdf | ⊢ ( 𝐺  ∈  Word  𝑆  →  𝐺 : ( 0 ..^ ( ♯ ‘ 𝐺 ) ) ⟶ 𝑆 ) | 
						
							| 60 | 2 59 | syl | ⊢ ( 𝜑  →  𝐺 : ( 0 ..^ ( ♯ ‘ 𝐺 ) ) ⟶ 𝑆 ) | 
						
							| 61 |  | ovexd | ⊢ ( 𝜑  →  ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ∈  V ) | 
						
							| 62 | 60 61 3 | ofcof | ⊢ ( 𝜑  →  ( 𝐺  ∘f/c  𝑅 𝐾 )  =  ( 𝐺  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) ) | 
						
							| 63 | 58 62 | oveq12d | ⊢ ( 𝜑  →  ( ( 𝐹  ∘f/c  𝑅 𝐾 )  ++  ( 𝐺  ∘f/c  𝑅 𝐾 ) )  =  ( ( 𝐹  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ 𝐹 ) )  ×  { 𝐾 } ) )  ++  ( 𝐺  ∘f  𝑅 ( ( 0 ..^ ( ♯ ‘ 𝐺 ) )  ×  { 𝐾 } ) ) ) ) | 
						
							| 64 | 37 54 63 | 3eqtr4d | ⊢ ( 𝜑  →  ( ( 𝐹  ++  𝐺 )  ∘f/c  𝑅 𝐾 )  =  ( ( 𝐹  ∘f/c  𝑅 𝐾 )  ++  ( 𝐺  ∘f/c  𝑅 𝐾 ) ) ) |