| Step | Hyp | Ref | Expression | 
						
							| 1 |  | mptelpm.b | ⊢ ( ( 𝜑  ∧  𝑥  ∈  𝐴 )  →  𝐵  ∈  𝐶 ) | 
						
							| 2 |  | mptelpm.a | ⊢ ( 𝜑  →  𝐴  ⊆  𝐷 ) | 
						
							| 3 |  | mptelpm.c | ⊢ ( 𝜑  →  𝐶  ∈  𝑉 ) | 
						
							| 4 |  | mptelpm.d | ⊢ ( 𝜑  →  𝐷  ∈  𝑊 ) | 
						
							| 5 | 1 | fmpttd | ⊢ ( 𝜑  →  ( 𝑥  ∈  𝐴  ↦  𝐵 ) : 𝐴 ⟶ 𝐶 ) | 
						
							| 6 |  | eqid | ⊢ ( 𝑥  ∈  𝐴  ↦  𝐵 )  =  ( 𝑥  ∈  𝐴  ↦  𝐵 ) | 
						
							| 7 | 6 1 | dmmptd | ⊢ ( 𝜑  →  dom  ( 𝑥  ∈  𝐴  ↦  𝐵 )  =  𝐴 ) | 
						
							| 8 | 7 | eqcomd | ⊢ ( 𝜑  →  𝐴  =  dom  ( 𝑥  ∈  𝐴  ↦  𝐵 ) ) | 
						
							| 9 | 8 | feq2d | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝐴  ↦  𝐵 ) : 𝐴 ⟶ 𝐶  ↔  ( 𝑥  ∈  𝐴  ↦  𝐵 ) : dom  ( 𝑥  ∈  𝐴  ↦  𝐵 ) ⟶ 𝐶 ) ) | 
						
							| 10 | 5 9 | mpbid | ⊢ ( 𝜑  →  ( 𝑥  ∈  𝐴  ↦  𝐵 ) : dom  ( 𝑥  ∈  𝐴  ↦  𝐵 ) ⟶ 𝐶 ) | 
						
							| 11 | 7 2 | eqsstrd | ⊢ ( 𝜑  →  dom  ( 𝑥  ∈  𝐴  ↦  𝐵 )  ⊆  𝐷 ) | 
						
							| 12 | 10 11 | jca | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝐴  ↦  𝐵 ) : dom  ( 𝑥  ∈  𝐴  ↦  𝐵 ) ⟶ 𝐶  ∧  dom  ( 𝑥  ∈  𝐴  ↦  𝐵 )  ⊆  𝐷 ) ) | 
						
							| 13 |  | elpm2g | ⊢ ( ( 𝐶  ∈  𝑉  ∧  𝐷  ∈  𝑊 )  →  ( ( 𝑥  ∈  𝐴  ↦  𝐵 )  ∈  ( 𝐶  ↑pm  𝐷 )  ↔  ( ( 𝑥  ∈  𝐴  ↦  𝐵 ) : dom  ( 𝑥  ∈  𝐴  ↦  𝐵 ) ⟶ 𝐶  ∧  dom  ( 𝑥  ∈  𝐴  ↦  𝐵 )  ⊆  𝐷 ) ) ) | 
						
							| 14 | 3 4 13 | syl2anc | ⊢ ( 𝜑  →  ( ( 𝑥  ∈  𝐴  ↦  𝐵 )  ∈  ( 𝐶  ↑pm  𝐷 )  ↔  ( ( 𝑥  ∈  𝐴  ↦  𝐵 ) : dom  ( 𝑥  ∈  𝐴  ↦  𝐵 ) ⟶ 𝐶  ∧  dom  ( 𝑥  ∈  𝐴  ↦  𝐵 )  ⊆  𝐷 ) ) ) | 
						
							| 15 | 12 14 | mpbird | ⊢ ( 𝜑  →  ( 𝑥  ∈  𝐴  ↦  𝐵 )  ∈  ( 𝐶  ↑pm  𝐷 ) ) |