Metamath Proof Explorer


Theorem evl1fval1lem

Description: Lemma for evl1fval1 . (Contributed by AV, 11-Sep-2019)

Ref Expression
Hypotheses evl1fval1.q Q = eval 1 R
evl1fval1.b B = Base R
Assertion evl1fval1lem R V Q = R evalSub 1 B

Proof

Step Hyp Ref Expression
1 evl1fval1.q Q = eval 1 R
2 evl1fval1.b B = Base R
3 eqid eval 1 R = eval 1 R
4 eqid 1 𝑜 eval R = 1 𝑜 eval R
5 3 4 2 evl1fval eval 1 R = x B B 1 𝑜 x y B 1 𝑜 × y 1 𝑜 eval R
6 1 a1i R V Q = eval 1 R
7 2 fvexi B V
8 7 pwid B 𝒫 B
9 eqid R evalSub 1 B = R evalSub 1 B
10 eqid 1 𝑜 evalSub R = 1 𝑜 evalSub R
11 9 10 2 evls1fval R V B 𝒫 B R evalSub 1 B = x B B 1 𝑜 x y B 1 𝑜 × y 1 𝑜 evalSub R B
12 8 11 mpan2 R V R evalSub 1 B = x B B 1 𝑜 x y B 1 𝑜 × y 1 𝑜 evalSub R B
13 4 2 evlval 1 𝑜 eval R = 1 𝑜 evalSub R B
14 13 eqcomi 1 𝑜 evalSub R B = 1 𝑜 eval R
15 14 coeq2i x B B 1 𝑜 x y B 1 𝑜 × y 1 𝑜 evalSub R B = x B B 1 𝑜 x y B 1 𝑜 × y 1 𝑜 eval R
16 12 15 eqtrdi R V R evalSub 1 B = x B B 1 𝑜 x y B 1 𝑜 × y 1 𝑜 eval R
17 5 6 16 3eqtr4a R V Q = R evalSub 1 B