| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simpr | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  𝑆  =  dom  ( ω  CNF  𝑋 ) ) | 
						
							| 2 | 1 | eleq2d | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐹  ∈  𝑆  ↔  𝐹  ∈  dom  ( ω  CNF  𝑋 ) ) ) | 
						
							| 3 |  | eqid | ⊢ dom  ( ω  CNF  𝑋 )  =  dom  ( ω  CNF  𝑋 ) | 
						
							| 4 |  | omelon | ⊢ ω  ∈  On | 
						
							| 5 | 4 | a1i | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ω  ∈  On ) | 
						
							| 6 |  | simpl | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  𝑋  ∈  On ) | 
						
							| 7 | 3 5 6 | cantnfs | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐹  ∈  dom  ( ω  CNF  𝑋 )  ↔  ( 𝐹 : 𝑋 ⟶ ω  ∧  𝐹  finSupp  ∅ ) ) ) | 
						
							| 8 | 2 7 | bitrd | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐹  ∈  𝑆  ↔  ( 𝐹 : 𝑋 ⟶ ω  ∧  𝐹  finSupp  ∅ ) ) ) | 
						
							| 9 |  | simpl | ⊢ ( ( 𝐹 : 𝑋 ⟶ ω  ∧  𝐹  finSupp  ∅ )  →  𝐹 : 𝑋 ⟶ ω ) | 
						
							| 10 | 9 | ffnd | ⊢ ( ( 𝐹 : 𝑋 ⟶ ω  ∧  𝐹  finSupp  ∅ )  →  𝐹  Fn  𝑋 ) | 
						
							| 11 | 8 10 | biimtrdi | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐹  ∈  𝑆  →  𝐹  Fn  𝑋 ) ) | 
						
							| 12 |  | simp1 | ⊢ ( ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 )  →  𝐹  ∈  𝑆 ) | 
						
							| 13 | 11 12 | impel | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  𝐹  Fn  𝑋 ) | 
						
							| 14 | 1 | eleq2d | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐺  ∈  𝑆  ↔  𝐺  ∈  dom  ( ω  CNF  𝑋 ) ) ) | 
						
							| 15 | 3 5 6 | cantnfs | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐺  ∈  dom  ( ω  CNF  𝑋 )  ↔  ( 𝐺 : 𝑋 ⟶ ω  ∧  𝐺  finSupp  ∅ ) ) ) | 
						
							| 16 | 14 15 | bitrd | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐺  ∈  𝑆  ↔  ( 𝐺 : 𝑋 ⟶ ω  ∧  𝐺  finSupp  ∅ ) ) ) | 
						
							| 17 |  | simpl | ⊢ ( ( 𝐺 : 𝑋 ⟶ ω  ∧  𝐺  finSupp  ∅ )  →  𝐺 : 𝑋 ⟶ ω ) | 
						
							| 18 | 17 | ffnd | ⊢ ( ( 𝐺 : 𝑋 ⟶ ω  ∧  𝐺  finSupp  ∅ )  →  𝐺  Fn  𝑋 ) | 
						
							| 19 | 16 18 | biimtrdi | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐺  ∈  𝑆  →  𝐺  Fn  𝑋 ) ) | 
						
							| 20 |  | simp2 | ⊢ ( ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 )  →  𝐺  ∈  𝑆 ) | 
						
							| 21 | 19 20 | impel | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  𝐺  Fn  𝑋 ) | 
						
							| 22 | 6 | adantr | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  𝑋  ∈  On ) | 
						
							| 23 |  | inidm | ⊢ ( 𝑋  ∩  𝑋 )  =  𝑋 | 
						
							| 24 | 13 21 22 22 23 | offn | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  ( 𝐹  ∘f   +o  𝐺 )  Fn  𝑋 ) | 
						
							| 25 | 1 | eleq2d | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐻  ∈  𝑆  ↔  𝐻  ∈  dom  ( ω  CNF  𝑋 ) ) ) | 
						
							| 26 | 3 5 6 | cantnfs | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐻  ∈  dom  ( ω  CNF  𝑋 )  ↔  ( 𝐻 : 𝑋 ⟶ ω  ∧  𝐻  finSupp  ∅ ) ) ) | 
						
							| 27 | 25 26 | bitrd | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐻  ∈  𝑆  ↔  ( 𝐻 : 𝑋 ⟶ ω  ∧  𝐻  finSupp  ∅ ) ) ) | 
						
							| 28 |  | simpl | ⊢ ( ( 𝐻 : 𝑋 ⟶ ω  ∧  𝐻  finSupp  ∅ )  →  𝐻 : 𝑋 ⟶ ω ) | 
						
							| 29 | 28 | ffnd | ⊢ ( ( 𝐻 : 𝑋 ⟶ ω  ∧  𝐻  finSupp  ∅ )  →  𝐻  Fn  𝑋 ) | 
						
							| 30 | 27 29 | biimtrdi | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐻  ∈  𝑆  →  𝐻  Fn  𝑋 ) ) | 
						
							| 31 |  | simp3 | ⊢ ( ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 )  →  𝐻  ∈  𝑆 ) | 
						
							| 32 | 30 31 | impel | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  𝐻  Fn  𝑋 ) | 
						
							| 33 | 24 32 22 22 23 | offn | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  ( ( 𝐹  ∘f   +o  𝐺 )  ∘f   +o  𝐻 )  Fn  𝑋 ) | 
						
							| 34 | 21 32 22 22 23 | offn | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  ( 𝐺  ∘f   +o  𝐻 )  Fn  𝑋 ) | 
						
							| 35 | 13 34 22 22 23 | offn | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  ( 𝐹  ∘f   +o  ( 𝐺  ∘f   +o  𝐻 ) )  Fn  𝑋 ) | 
						
							| 36 | 8 9 | biimtrdi | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐹  ∈  𝑆  →  𝐹 : 𝑋 ⟶ ω ) ) | 
						
							| 37 | 36 12 | impel | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  𝐹 : 𝑋 ⟶ ω ) | 
						
							| 38 | 37 | ffvelcdmda | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( 𝐹 ‘ 𝑥 )  ∈  ω ) | 
						
							| 39 | 16 17 | biimtrdi | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐺  ∈  𝑆  →  𝐺 : 𝑋 ⟶ ω ) ) | 
						
							| 40 | 39 20 | impel | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  𝐺 : 𝑋 ⟶ ω ) | 
						
							| 41 | 40 | ffvelcdmda | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( 𝐺 ‘ 𝑥 )  ∈  ω ) | 
						
							| 42 | 27 28 | biimtrdi | ⊢ ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  →  ( 𝐻  ∈  𝑆  →  𝐻 : 𝑋 ⟶ ω ) ) | 
						
							| 43 | 42 31 | impel | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  𝐻 : 𝑋 ⟶ ω ) | 
						
							| 44 | 43 | ffvelcdmda | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( 𝐻 ‘ 𝑥 )  ∈  ω ) | 
						
							| 45 |  | nnaass | ⊢ ( ( ( 𝐹 ‘ 𝑥 )  ∈  ω  ∧  ( 𝐺 ‘ 𝑥 )  ∈  ω  ∧  ( 𝐻 ‘ 𝑥 )  ∈  ω )  →  ( ( ( 𝐹 ‘ 𝑥 )  +o  ( 𝐺 ‘ 𝑥 ) )  +o  ( 𝐻 ‘ 𝑥 ) )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( ( 𝐺 ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) ) ) ) | 
						
							| 46 | 38 41 44 45 | syl3anc | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( ( 𝐹 ‘ 𝑥 )  +o  ( 𝐺 ‘ 𝑥 ) )  +o  ( 𝐻 ‘ 𝑥 ) )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( ( 𝐺 ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) ) ) ) | 
						
							| 47 | 13 | adantr | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  𝐹  Fn  𝑋 ) | 
						
							| 48 | 21 | adantr | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  𝐺  Fn  𝑋 ) | 
						
							| 49 | 22 | anim1i | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( 𝑋  ∈  On  ∧  𝑥  ∈  𝑋 ) ) | 
						
							| 50 |  | fnfvof | ⊢ ( ( ( 𝐹  Fn  𝑋  ∧  𝐺  Fn  𝑋 )  ∧  ( 𝑋  ∈  On  ∧  𝑥  ∈  𝑋 ) )  →  ( ( 𝐹  ∘f   +o  𝐺 ) ‘ 𝑥 )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( 𝐺 ‘ 𝑥 ) ) ) | 
						
							| 51 | 47 48 49 50 | syl21anc | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( 𝐹  ∘f   +o  𝐺 ) ‘ 𝑥 )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( 𝐺 ‘ 𝑥 ) ) ) | 
						
							| 52 | 51 | oveq1d | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( ( 𝐹  ∘f   +o  𝐺 ) ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) )  =  ( ( ( 𝐹 ‘ 𝑥 )  +o  ( 𝐺 ‘ 𝑥 ) )  +o  ( 𝐻 ‘ 𝑥 ) ) ) | 
						
							| 53 | 32 | adantr | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  𝐻  Fn  𝑋 ) | 
						
							| 54 |  | fnfvof | ⊢ ( ( ( 𝐺  Fn  𝑋  ∧  𝐻  Fn  𝑋 )  ∧  ( 𝑋  ∈  On  ∧  𝑥  ∈  𝑋 ) )  →  ( ( 𝐺  ∘f   +o  𝐻 ) ‘ 𝑥 )  =  ( ( 𝐺 ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) ) ) | 
						
							| 55 | 48 53 49 54 | syl21anc | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( 𝐺  ∘f   +o  𝐻 ) ‘ 𝑥 )  =  ( ( 𝐺 ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) ) ) | 
						
							| 56 | 55 | oveq2d | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( 𝐹 ‘ 𝑥 )  +o  ( ( 𝐺  ∘f   +o  𝐻 ) ‘ 𝑥 ) )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( ( 𝐺 ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) ) ) ) | 
						
							| 57 | 46 52 56 | 3eqtr4d | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( ( 𝐹  ∘f   +o  𝐺 ) ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( ( 𝐺  ∘f   +o  𝐻 ) ‘ 𝑥 ) ) ) | 
						
							| 58 | 24 | adantr | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( 𝐹  ∘f   +o  𝐺 )  Fn  𝑋 ) | 
						
							| 59 |  | fnfvof | ⊢ ( ( ( ( 𝐹  ∘f   +o  𝐺 )  Fn  𝑋  ∧  𝐻  Fn  𝑋 )  ∧  ( 𝑋  ∈  On  ∧  𝑥  ∈  𝑋 ) )  →  ( ( ( 𝐹  ∘f   +o  𝐺 )  ∘f   +o  𝐻 ) ‘ 𝑥 )  =  ( ( ( 𝐹  ∘f   +o  𝐺 ) ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) ) ) | 
						
							| 60 | 58 53 49 59 | syl21anc | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( ( 𝐹  ∘f   +o  𝐺 )  ∘f   +o  𝐻 ) ‘ 𝑥 )  =  ( ( ( 𝐹  ∘f   +o  𝐺 ) ‘ 𝑥 )  +o  ( 𝐻 ‘ 𝑥 ) ) ) | 
						
							| 61 | 34 | adantr | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( 𝐺  ∘f   +o  𝐻 )  Fn  𝑋 ) | 
						
							| 62 |  | fnfvof | ⊢ ( ( ( 𝐹  Fn  𝑋  ∧  ( 𝐺  ∘f   +o  𝐻 )  Fn  𝑋 )  ∧  ( 𝑋  ∈  On  ∧  𝑥  ∈  𝑋 ) )  →  ( ( 𝐹  ∘f   +o  ( 𝐺  ∘f   +o  𝐻 ) ) ‘ 𝑥 )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( ( 𝐺  ∘f   +o  𝐻 ) ‘ 𝑥 ) ) ) | 
						
							| 63 | 47 61 49 62 | syl21anc | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( 𝐹  ∘f   +o  ( 𝐺  ∘f   +o  𝐻 ) ) ‘ 𝑥 )  =  ( ( 𝐹 ‘ 𝑥 )  +o  ( ( 𝐺  ∘f   +o  𝐻 ) ‘ 𝑥 ) ) ) | 
						
							| 64 | 57 60 63 | 3eqtr4d | ⊢ ( ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  ∧  𝑥  ∈  𝑋 )  →  ( ( ( 𝐹  ∘f   +o  𝐺 )  ∘f   +o  𝐻 ) ‘ 𝑥 )  =  ( ( 𝐹  ∘f   +o  ( 𝐺  ∘f   +o  𝐻 ) ) ‘ 𝑥 ) ) | 
						
							| 65 | 33 35 64 | eqfnfvd | ⊢ ( ( ( 𝑋  ∈  On  ∧  𝑆  =  dom  ( ω  CNF  𝑋 ) )  ∧  ( 𝐹  ∈  𝑆  ∧  𝐺  ∈  𝑆  ∧  𝐻  ∈  𝑆 ) )  →  ( ( 𝐹  ∘f   +o  𝐺 )  ∘f   +o  𝐻 )  =  ( 𝐹  ∘f   +o  ( 𝐺  ∘f   +o  𝐻 ) ) ) |