Metamath Proof Explorer


Theorem funexw

Description: Weak version of funex that holds without ax-rep . If the domain and codomain of a function exist, so does the function. (Contributed by Rohan Ridenour, 13-Aug-2023)

Ref Expression
Assertion funexw Fun F dom F B ran F C F V

Proof

Step Hyp Ref Expression
1 xpexg dom F B ran F C dom F × ran F V
2 1 3adant1 Fun F dom F B ran F C dom F × ran F V
3 funrel Fun F Rel F
4 relssdmrn Rel F F dom F × ran F
5 3 4 syl Fun F F dom F × ran F
6 5 3ad2ant1 Fun F dom F B ran F C F dom F × ran F
7 2 6 ssexd Fun F dom F B ran F C F V