Metamath Proof Explorer


Theorem mbfmptcl

Description: Lemma for the MblFn predicate applied to a mapping operation. (Contributed by Mario Carneiro, 11-Aug-2014)

Ref Expression
Hypotheses mbfmptcl.1 ( 𝜑 → ( 𝑥𝐴𝐵 ) ∈ MblFn )
mbfmptcl.2 ( ( 𝜑𝑥𝐴 ) → 𝐵𝑉 )
Assertion mbfmptcl ( ( 𝜑𝑥𝐴 ) → 𝐵 ∈ ℂ )

Proof

Step Hyp Ref Expression
1 mbfmptcl.1 ( 𝜑 → ( 𝑥𝐴𝐵 ) ∈ MblFn )
2 mbfmptcl.2 ( ( 𝜑𝑥𝐴 ) → 𝐵𝑉 )
3 mbff ( ( 𝑥𝐴𝐵 ) ∈ MblFn → ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ ℂ )
4 1 3 syl ( 𝜑 → ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ ℂ )
5 2 ralrimiva ( 𝜑 → ∀ 𝑥𝐴 𝐵𝑉 )
6 dmmptg ( ∀ 𝑥𝐴 𝐵𝑉 → dom ( 𝑥𝐴𝐵 ) = 𝐴 )
7 5 6 syl ( 𝜑 → dom ( 𝑥𝐴𝐵 ) = 𝐴 )
8 7 feq2d ( 𝜑 → ( ( 𝑥𝐴𝐵 ) : dom ( 𝑥𝐴𝐵 ) ⟶ ℂ ↔ ( 𝑥𝐴𝐵 ) : 𝐴 ⟶ ℂ ) )
9 4 8 mpbid ( 𝜑 → ( 𝑥𝐴𝐵 ) : 𝐴 ⟶ ℂ )
10 9 fvmptelrn ( ( 𝜑𝑥𝐴 ) → 𝐵 ∈ ℂ )