Metamath Proof Explorer


Theorem 1cossxrncnvepresex

Description: Sufficient condition for a restricted converse epsilon range Cartesian product to be a set. (Contributed by Peter Mazsa, 23-Sep-2021)

Ref Expression
Assertion 1cossxrncnvepresex A V R W R E -1 A V

Proof

Step Hyp Ref Expression
1 xrncnvepresex A V R W R E -1 A V
2 cossex R E -1 A V R E -1 A V
3 1 2 syl A V R W R E -1 A V