Metamath Proof Explorer


Theorem elpm2r

Description: Sufficient condition for being a partial function. (Contributed by NM, 31-Dec-2013)

Ref Expression
Assertion elpm2r ( ( ( 𝐴𝑉𝐵𝑊 ) ∧ ( 𝐹 : 𝐶𝐴𝐶𝐵 ) ) → 𝐹 ∈ ( 𝐴pm 𝐵 ) )

Proof

Step Hyp Ref Expression
1 fdm ( 𝐹 : 𝐶𝐴 → dom 𝐹 = 𝐶 )
2 1 feq2d ( 𝐹 : 𝐶𝐴 → ( 𝐹 : dom 𝐹𝐴𝐹 : 𝐶𝐴 ) )
3 1 sseq1d ( 𝐹 : 𝐶𝐴 → ( dom 𝐹𝐵𝐶𝐵 ) )
4 2 3 anbi12d ( 𝐹 : 𝐶𝐴 → ( ( 𝐹 : dom 𝐹𝐴 ∧ dom 𝐹𝐵 ) ↔ ( 𝐹 : 𝐶𝐴𝐶𝐵 ) ) )
5 4 adantr ( ( 𝐹 : 𝐶𝐴𝐶𝐵 ) → ( ( 𝐹 : dom 𝐹𝐴 ∧ dom 𝐹𝐵 ) ↔ ( 𝐹 : 𝐶𝐴𝐶𝐵 ) ) )
6 5 ibir ( ( 𝐹 : 𝐶𝐴𝐶𝐵 ) → ( 𝐹 : dom 𝐹𝐴 ∧ dom 𝐹𝐵 ) )
7 elpm2g ( ( 𝐴𝑉𝐵𝑊 ) → ( 𝐹 ∈ ( 𝐴pm 𝐵 ) ↔ ( 𝐹 : dom 𝐹𝐴 ∧ dom 𝐹𝐵 ) ) )
8 6 7 syl5ibr ( ( 𝐴𝑉𝐵𝑊 ) → ( ( 𝐹 : 𝐶𝐴𝐶𝐵 ) → 𝐹 ∈ ( 𝐴pm 𝐵 ) ) )
9 8 imp ( ( ( 𝐴𝑉𝐵𝑊 ) ∧ ( 𝐹 : 𝐶𝐴𝐶𝐵 ) ) → 𝐹 ∈ ( 𝐴pm 𝐵 ) )