Metamath Proof Explorer


Theorem resvval2

Description: Value of nontrivial structure restriction. (Contributed by Thierry Arnoux, 6-Sep-2018)

Ref Expression
Hypotheses resvsca.r R = W 𝑣 A
resvsca.f F = Scalar W
resvsca.b B = Base F
Assertion resvval2 ¬ B A W X A Y R = W sSet Scalar ndx F 𝑠 A

Proof

Step Hyp Ref Expression
1 resvsca.r R = W 𝑣 A
2 resvsca.f F = Scalar W
3 resvsca.b B = Base F
4 1 2 3 resvval W X A Y R = if B A W W sSet Scalar ndx F 𝑠 A
5 iffalse ¬ B A if B A W W sSet Scalar ndx F 𝑠 A = W sSet Scalar ndx F 𝑠 A
6 4 5 sylan9eqr ¬ B A W X A Y R = W sSet Scalar ndx F 𝑠 A
7 6 3impb ¬ B A W X A Y R = W sSet Scalar ndx F 𝑠 A