| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ovexd | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∈  V ) | 
						
							| 2 |  | ovexd | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) )  ∈  V ) | 
						
							| 3 |  | elmapi | ⊢ ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  →  𝑓 : 𝐶 ⟶ ( 𝐴  ↑m  𝐵 ) ) | 
						
							| 4 | 3 | ffvelcdmda | ⊢ ( ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑓 ‘ 𝑦 )  ∈  ( 𝐴  ↑m  𝐵 ) ) | 
						
							| 5 |  | elmapi | ⊢ ( ( 𝑓 ‘ 𝑦 )  ∈  ( 𝐴  ↑m  𝐵 )  →  ( 𝑓 ‘ 𝑦 ) : 𝐵 ⟶ 𝐴 ) | 
						
							| 6 | 4 5 | syl | ⊢ ( ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑓 ‘ 𝑦 ) : 𝐵 ⟶ 𝐴 ) | 
						
							| 7 | 6 | ffvelcdmda | ⊢ ( ( ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑦  ∈  𝐶 )  ∧  𝑥  ∈  𝐵 )  →  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ∈  𝐴 ) | 
						
							| 8 | 7 | an32s | ⊢ ( ( ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑥  ∈  𝐵 )  ∧  𝑦  ∈  𝐶 )  →  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ∈  𝐴 ) | 
						
							| 9 | 8 | ralrimiva | ⊢ ( ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑥  ∈  𝐵 )  →  ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ∈  𝐴 ) | 
						
							| 10 | 9 | ralrimiva | ⊢ ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  →  ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ∈  𝐴 ) | 
						
							| 11 |  | eqid | ⊢ ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 12 | 11 | fmpo | ⊢ ( ∀ 𝑥  ∈  𝐵 ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ∈  𝐴  ↔  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) : ( 𝐵  ×  𝐶 ) ⟶ 𝐴 ) | 
						
							| 13 | 10 12 | sylib | ⊢ ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  →  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) : ( 𝐵  ×  𝐶 ) ⟶ 𝐴 ) | 
						
							| 14 |  | simp1 | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  𝐴  ∈  𝑉 ) | 
						
							| 15 |  | xpexg | ⊢ ( ( 𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( 𝐵  ×  𝐶 )  ∈  V ) | 
						
							| 16 | 15 | 3adant1 | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( 𝐵  ×  𝐶 )  ∈  V ) | 
						
							| 17 |  | elmapg | ⊢ ( ( 𝐴  ∈  𝑉  ∧  ( 𝐵  ×  𝐶 )  ∈  V )  →  ( ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) )  ↔  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) : ( 𝐵  ×  𝐶 ) ⟶ 𝐴 ) ) | 
						
							| 18 | 14 16 17 | syl2anc | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) )  ↔  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) : ( 𝐵  ×  𝐶 ) ⟶ 𝐴 ) ) | 
						
							| 19 | 13 18 | imbitrrid | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  →  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) ) | 
						
							| 20 |  | elmapi | ⊢ ( 𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) )  →  𝑔 : ( 𝐵  ×  𝐶 ) ⟶ 𝐴 ) | 
						
							| 21 | 20 | adantl | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) )  →  𝑔 : ( 𝐵  ×  𝐶 ) ⟶ 𝐴 ) | 
						
							| 22 |  | fovcdm | ⊢ ( ( 𝑔 : ( 𝐵  ×  𝐶 ) ⟶ 𝐴  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥 𝑔 𝑦 )  ∈  𝐴 ) | 
						
							| 23 | 22 | 3expa | ⊢ ( ( ( 𝑔 : ( 𝐵  ×  𝐶 ) ⟶ 𝐴  ∧  𝑥  ∈  𝐵 )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥 𝑔 𝑦 )  ∈  𝐴 ) | 
						
							| 24 | 23 | an32s | ⊢ ( ( ( 𝑔 : ( 𝐵  ×  𝐶 ) ⟶ 𝐴  ∧  𝑦  ∈  𝐶 )  ∧  𝑥  ∈  𝐵 )  →  ( 𝑥 𝑔 𝑦 )  ∈  𝐴 ) | 
						
							| 25 | 21 24 | sylanl1 | ⊢ ( ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) )  ∧  𝑦  ∈  𝐶 )  ∧  𝑥  ∈  𝐵 )  →  ( 𝑥 𝑔 𝑦 )  ∈  𝐴 ) | 
						
							| 26 | 25 | fmpttd | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) : 𝐵 ⟶ 𝐴 ) | 
						
							| 27 |  | elmapg | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊 )  →  ( ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  ∈  ( 𝐴  ↑m  𝐵 )  ↔  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) : 𝐵 ⟶ 𝐴 ) ) | 
						
							| 28 | 27 | 3adant3 | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  ∈  ( 𝐴  ↑m  𝐵 )  ↔  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) : 𝐵 ⟶ 𝐴 ) ) | 
						
							| 29 | 28 | ad2antrr | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) )  ∧  𝑦  ∈  𝐶 )  →  ( ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  ∈  ( 𝐴  ↑m  𝐵 )  ↔  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) : 𝐵 ⟶ 𝐴 ) ) | 
						
							| 30 | 26 29 | mpbird | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  ∈  ( 𝐴  ↑m  𝐵 ) ) | 
						
							| 31 | 30 | fmpttd | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) )  →  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) : 𝐶 ⟶ ( 𝐴  ↑m  𝐵 ) ) | 
						
							| 32 | 31 | ex | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( 𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) )  →  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) : 𝐶 ⟶ ( 𝐴  ↑m  𝐵 ) ) ) | 
						
							| 33 |  | ovex | ⊢ ( 𝐴  ↑m  𝐵 )  ∈  V | 
						
							| 34 |  | simp3 | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  𝐶  ∈  𝑋 ) | 
						
							| 35 |  | elmapg | ⊢ ( ( ( 𝐴  ↑m  𝐵 )  ∈  V  ∧  𝐶  ∈  𝑋 )  →  ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ↔  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) : 𝐶 ⟶ ( 𝐴  ↑m  𝐵 ) ) ) | 
						
							| 36 | 33 34 35 | sylancr | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ↔  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) : 𝐶 ⟶ ( 𝐴  ↑m  𝐵 ) ) ) | 
						
							| 37 | 32 36 | sylibrd | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( 𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) )  →  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 ) ) ) | 
						
							| 38 |  | elmapfn | ⊢ ( 𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) )  →  𝑔  Fn  ( 𝐵  ×  𝐶 ) ) | 
						
							| 39 | 38 | ad2antll | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  𝑔  Fn  ( 𝐵  ×  𝐶 ) ) | 
						
							| 40 |  | fnov | ⊢ ( 𝑔  Fn  ( 𝐵  ×  𝐶 )  ↔  𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 41 | 39 40 | sylib | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 42 |  | simp3 | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  𝑦  ∈  𝐶 ) | 
						
							| 43 | 26 | adantlrl | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) : 𝐵 ⟶ 𝐴 ) | 
						
							| 44 | 43 | 3adant2 | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) : 𝐵 ⟶ 𝐴 ) | 
						
							| 45 |  | simp1l2 | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  𝐵  ∈  𝑊 ) | 
						
							| 46 |  | simp1l1 | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  𝐴  ∈  𝑉 ) | 
						
							| 47 |  | fex2 | ⊢ ( ( ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) : 𝐵 ⟶ 𝐴  ∧  𝐵  ∈  𝑊  ∧  𝐴  ∈  𝑉 )  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  ∈  V ) | 
						
							| 48 | 44 45 46 47 | syl3anc | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  ∈  V ) | 
						
							| 49 |  | eqid | ⊢ ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 50 | 49 | fvmpt2 | ⊢ ( ( 𝑦  ∈  𝐶  ∧  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  ∈  V )  →  ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 )  =  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 51 | 42 48 50 | syl2anc | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 )  =  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 52 | 51 | fveq1d | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ‘ 𝑥 ) ) | 
						
							| 53 |  | simp2 | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  𝑥  ∈  𝐵 ) | 
						
							| 54 |  | ovex | ⊢ ( 𝑥 𝑔 𝑦 )  ∈  V | 
						
							| 55 |  | eqid | ⊢ ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  =  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) | 
						
							| 56 | 55 | fvmpt2 | ⊢ ( ( 𝑥  ∈  𝐵  ∧  ( 𝑥 𝑔 𝑦 )  ∈  V )  →  ( ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ‘ 𝑥 )  =  ( 𝑥 𝑔 𝑦 ) ) | 
						
							| 57 | 53 54 56 | sylancl | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ‘ 𝑥 )  =  ( 𝑥 𝑔 𝑦 ) ) | 
						
							| 58 | 52 57 | eqtrd | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 )  =  ( 𝑥 𝑔 𝑦 ) ) | 
						
							| 59 | 58 | mpoeq3dva | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 60 | 41 59 | eqtr4d | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 61 |  | eqid | ⊢ 𝐵  =  𝐵 | 
						
							| 62 |  | nfcv | ⊢ Ⅎ 𝑥 𝐶 | 
						
							| 63 |  | nfmpt1 | ⊢ Ⅎ 𝑥 ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) | 
						
							| 64 | 62 63 | nfmpt | ⊢ Ⅎ 𝑥 ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 65 | 64 | nfeq2 | ⊢ Ⅎ 𝑥 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 66 |  | nfmpt1 | ⊢ Ⅎ 𝑦 ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 67 | 66 | nfeq2 | ⊢ Ⅎ 𝑦 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) | 
						
							| 68 |  | fveq1 | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ( 𝑓 ‘ 𝑦 )  =  ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ) | 
						
							| 69 | 68 | fveq1d | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 70 | 69 | a1d | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ( 𝑦  ∈  𝐶  →  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 71 | 67 70 | ralrimi | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 72 |  | eqid | ⊢ 𝐶  =  𝐶 | 
						
							| 73 | 71 72 | jctil | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ( 𝐶  =  𝐶  ∧  ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 74 | 73 | a1d | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ( 𝑥  ∈  𝐵  →  ( 𝐶  =  𝐶  ∧  ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 75 | 65 74 | ralrimi | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ∀ 𝑥  ∈  𝐵 ( 𝐶  =  𝐶  ∧  ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 76 |  | mpoeq123 | ⊢ ( ( 𝐵  =  𝐵  ∧  ∀ 𝑥  ∈  𝐵 ( 𝐶  =  𝐶  ∧  ∀ 𝑦  ∈  𝐶 ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  =  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) )  →  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 77 | 61 75 76 | sylancr | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 78 | 77 | eqeq2d | ⊢ ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  ↔  𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 79 | 60 78 | syl5ibrcom | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  →  𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 80 | 3 | ad2antrl | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  𝑓 : 𝐶 ⟶ ( 𝐴  ↑m  𝐵 ) ) | 
						
							| 81 | 80 | feqmptd | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑓 ‘ 𝑦 ) ) ) | 
						
							| 82 |  | simprl | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 ) ) | 
						
							| 83 | 82 6 | sylan | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑓 ‘ 𝑦 ) : 𝐵 ⟶ 𝐴 ) | 
						
							| 84 | 83 | feqmptd | ⊢ ( ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  ∧  𝑦  ∈  𝐶 )  →  ( 𝑓 ‘ 𝑦 )  =  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 85 | 84 | mpteq2dva | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  ( 𝑦  ∈  𝐶  ↦  ( 𝑓 ‘ 𝑦 ) )  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 86 | 81 85 | eqtrd | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 87 |  | nfmpo2 | ⊢ Ⅎ 𝑦 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 88 | 87 | nfeq2 | ⊢ Ⅎ 𝑦 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 89 |  | eqidd | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  𝐵  =  𝐵 ) | 
						
							| 90 |  | nfmpo1 | ⊢ Ⅎ 𝑥 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 91 | 90 | nfeq2 | ⊢ Ⅎ 𝑥 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 92 |  | nfv | ⊢ Ⅎ 𝑥 𝑦  ∈  𝐶 | 
						
							| 93 |  | fvex | ⊢ ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ∈  V | 
						
							| 94 | 11 | ovmpt4g | ⊢ ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶  ∧  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ∈  V )  →  ( 𝑥 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 95 | 93 94 | mp3an3 | ⊢ ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) | 
						
							| 96 |  | oveq | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( 𝑥 𝑔 𝑦 )  =  ( 𝑥 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) 𝑦 ) ) | 
						
							| 97 | 96 | eqeq1d | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( ( 𝑥 𝑔 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 )  ↔  ( 𝑥 ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 98 | 95 97 | imbitrrid | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( ( 𝑥  ∈  𝐵  ∧  𝑦  ∈  𝐶 )  →  ( 𝑥 𝑔 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 99 | 98 | expcomd | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( 𝑦  ∈  𝐶  →  ( 𝑥  ∈  𝐵  →  ( 𝑥 𝑔 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 100 | 91 92 99 | ralrimd | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( 𝑦  ∈  𝐶  →  ∀ 𝑥  ∈  𝐵 ( 𝑥 𝑔 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 101 |  | mpteq12 | ⊢ ( ( 𝐵  =  𝐵  ∧  ∀ 𝑥  ∈  𝐵 ( 𝑥 𝑔 𝑦 )  =  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  =  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 102 | 89 100 101 | syl6an | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( 𝑦  ∈  𝐶  →  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  =  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 103 | 88 102 | ralrimi | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ∀ 𝑦  ∈  𝐶 ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  =  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) | 
						
							| 104 |  | mpteq12 | ⊢ ( ( 𝐶  =  𝐶  ∧  ∀ 𝑦  ∈  𝐶 ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) )  =  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) )  →  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 105 | 72 103 104 | sylancr | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 106 | 105 | eqeq2d | ⊢ ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  ↔  𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) ) | 
						
							| 107 | 86 106 | syl5ibrcom | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  ( 𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) )  →  𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) ) ) ) | 
						
							| 108 | 79 107 | impbid | ⊢ ( ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  ∧  ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) )  →  ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  ↔  𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) | 
						
							| 109 | 108 | ex | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( ( 𝑓  ∈  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ∧  𝑔  ∈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) )  →  ( 𝑓  =  ( 𝑦  ∈  𝐶  ↦  ( 𝑥  ∈  𝐵  ↦  ( 𝑥 𝑔 𝑦 ) ) )  ↔  𝑔  =  ( 𝑥  ∈  𝐵 ,  𝑦  ∈  𝐶  ↦  ( ( 𝑓 ‘ 𝑦 ) ‘ 𝑥 ) ) ) ) ) | 
						
							| 110 | 1 2 19 37 109 | en3d | ⊢ ( ( 𝐴  ∈  𝑉  ∧  𝐵  ∈  𝑊  ∧  𝐶  ∈  𝑋 )  →  ( ( 𝐴  ↑m  𝐵 )  ↑m  𝐶 )  ≈  ( 𝐴  ↑m  ( 𝐵  ×  𝐶 ) ) ) |