Metamath Proof Explorer


Theorem fvopabf4g

Description: Function value of an operator abstraction whose domain is a set of functions with given domain and range. (Contributed by Jeff Madsen, 1-Dec-2009) (Revised by Mario Carneiro, 12-Sep-2015)

Ref Expression
Hypotheses fvopabf4g.1 𝐶 ∈ V
fvopabf4g.2 ( 𝑥 = 𝐴𝐵 = 𝐶 )
fvopabf4g.3 𝐹 = ( 𝑥 ∈ ( 𝑅m 𝐷 ) ↦ 𝐵 )
Assertion fvopabf4g ( ( 𝐷𝑋𝑅𝑌𝐴 : 𝐷𝑅 ) → ( 𝐹𝐴 ) = 𝐶 )

Proof

Step Hyp Ref Expression
1 fvopabf4g.1 𝐶 ∈ V
2 fvopabf4g.2 ( 𝑥 = 𝐴𝐵 = 𝐶 )
3 fvopabf4g.3 𝐹 = ( 𝑥 ∈ ( 𝑅m 𝐷 ) ↦ 𝐵 )
4 elmapg ( ( 𝑅𝑌𝐷𝑋 ) → ( 𝐴 ∈ ( 𝑅m 𝐷 ) ↔ 𝐴 : 𝐷𝑅 ) )
5 4 ancoms ( ( 𝐷𝑋𝑅𝑌 ) → ( 𝐴 ∈ ( 𝑅m 𝐷 ) ↔ 𝐴 : 𝐷𝑅 ) )
6 5 biimp3ar ( ( 𝐷𝑋𝑅𝑌𝐴 : 𝐷𝑅 ) → 𝐴 ∈ ( 𝑅m 𝐷 ) )
7 2 3 1 fvmpt ( 𝐴 ∈ ( 𝑅m 𝐷 ) → ( 𝐹𝐴 ) = 𝐶 )
8 6 7 syl ( ( 𝐷𝑋𝑅𝑌𝐴 : 𝐷𝑅 ) → ( 𝐹𝐴 ) = 𝐶 )