Metamath Proof Explorer


Theorem neg1ne0

Description: -1 is nonzero. (Contributed by David A. Wheeler, 8-Dec-2018)

Ref Expression
Assertion neg1ne0 1 0

Proof

Step Hyp Ref Expression
1 ax-1cn 1
2 ax-1ne0 1 0
3 1 2 negne0i 1 0