Metamath Proof Explorer


Theorem fvn0elsupp

Description: If the function value for a given argument is not empty, the argument belongs to the support of the function with the empty set as zero. (Contributed by AV, 2-Jul-2019) (Revised by AV, 4-Apr-2020)

Ref Expression
Assertion fvn0elsupp B V X B G Fn B G X X supp G

Proof

Step Hyp Ref Expression
1 simpr B V X B X B
2 simpr G Fn B G X G X
3 1 2 anim12i B V X B G Fn B G X X B G X
4 simprl B V X B G Fn B G X G Fn B
5 simpll B V X B G Fn B G X B V
6 0ex V
7 6 a1i B V X B G Fn B G X V
8 elsuppfn G Fn B B V V X supp G X B G X
9 4 5 7 8 syl3anc B V X B G Fn B G X X supp G X B G X
10 3 9 mpbird B V X B G Fn B G X X supp G