Metamath Proof Explorer


Theorem mptelpm

Description: A function in maps-to notation is a partial map . (Contributed by Glauco Siliprandi, 5-Apr-2020)

Ref Expression
Hypotheses mptelpm.b ( ( 𝜑𝑥𝐴 ) → 𝐵𝐶 )
mptelpm.a ( 𝜑𝐴𝐷 )
mptelpm.c ( 𝜑𝐶𝑉 )
mptelpm.d ( 𝜑𝐷𝑊 )
Assertion mptelpm ( 𝜑 → ( 𝑥𝐴𝐵 ) ∈ ( 𝐶pm 𝐷 ) )

Proof

Step Hyp Ref Expression
1 mptelpm.b ( ( 𝜑𝑥𝐴 ) → 𝐵𝐶 )
2 mptelpm.a ( 𝜑𝐴𝐷 )
3 mptelpm.c ( 𝜑𝐶𝑉 )
4 mptelpm.d ( 𝜑𝐷𝑊 )
5 1 fmpttd ( 𝜑 → ( 𝑥𝐴𝐵 ) : 𝐴𝐶 )
6 eqid ( 𝑥𝐴𝐵 ) = ( 𝑥𝐴𝐵 )
7 6 1 dmmptd ( 𝜑 → dom ( 𝑥𝐴𝐵 ) = 𝐴 )
8 7 eqcomd ( 𝜑𝐴 = dom ( 𝑥𝐴𝐵 ) )
9 8 feq2d ( 𝜑 → ( ( 𝑥𝐴𝐵 ) : 𝐴𝐶 ↔ ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ 𝐶 ) )
10 5 9 mpbid ( 𝜑 → ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ 𝐶 )
11 7 2 eqsstrd ( 𝜑 → dom ( 𝑥𝐴𝐵 ) ⊆ 𝐷 )
12 10 11 jca ( 𝜑 → ( ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ 𝐶 ∧ dom ( 𝑥𝐴𝐵 ) ⊆ 𝐷 ) )
13 elpm2g ( ( 𝐶𝑉𝐷𝑊 ) → ( ( 𝑥𝐴𝐵 ) ∈ ( 𝐶pm 𝐷 ) ↔ ( ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ 𝐶 ∧ dom ( 𝑥𝐴𝐵 ) ⊆ 𝐷 ) ) )
14 3 4 13 syl2anc ( 𝜑 → ( ( 𝑥𝐴𝐵 ) ∈ ( 𝐶pm 𝐷 ) ↔ ( ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ 𝐶 ∧ dom ( 𝑥𝐴𝐵 ) ⊆ 𝐷 ) ) )
15 12 14 mpbird ( 𝜑 → ( 𝑥𝐴𝐵 ) ∈ ( 𝐶pm 𝐷 ) )