Metamath Proof Explorer


Theorem imasaddflem

Description: The image set operations are closed if the original operation is. (Contributed by Mario Carneiro, 23-Feb-2015)

Ref Expression
Hypotheses imasaddf.f φ F : V onto B
imasaddf.e φ a V b V p V q V F a = F p F b = F q F a · ˙ b = F p · ˙ q
imasaddflem.a φ ˙ = p V q V F p F q F p · ˙ q
imasaddflem.c φ p V q V p · ˙ q V
Assertion imasaddflem φ ˙ : B × B B

Proof

Step Hyp Ref Expression
1 imasaddf.f φ F : V onto B
2 imasaddf.e φ a V b V p V q V F a = F p F b = F q F a · ˙ b = F p · ˙ q
3 imasaddflem.a φ ˙ = p V q V F p F q F p · ˙ q
4 imasaddflem.c φ p V q V p · ˙ q V
5 1 2 3 imasaddfnlem φ ˙ Fn B × B
6 fof F : V onto B F : V B
7 1 6 syl φ F : V B
8 ffvelrn F : V B p V F p B
9 ffvelrn F : V B q V F q B
10 8 9 anim12dan F : V B p V q V F p B F q B
11 opelxpi F p B F q B F p F q B × B
12 10 11 syl F : V B p V q V F p F q B × B
13 7 12 sylan φ p V q V F p F q B × B
14 ffvelrn F : V B p · ˙ q V F p · ˙ q B
15 7 4 14 syl2an2r φ p V q V F p · ˙ q B
16 13 15 opelxpd φ p V q V F p F q F p · ˙ q B × B × B
17 16 snssd φ p V q V F p F q F p · ˙ q B × B × B
18 17 anassrs φ p V q V F p F q F p · ˙ q B × B × B
19 18 iunssd φ p V q V F p F q F p · ˙ q B × B × B
20 19 iunssd φ p V q V F p F q F p · ˙ q B × B × B
21 3 20 eqsstrd φ ˙ B × B × B
22 dff2 ˙ : B × B B ˙ Fn B × B ˙ B × B × B
23 5 21 22 sylanbrc φ ˙ : B × B B