Metamath Proof Explorer


Theorem le0neg1d

Description: Comparison of a number and its negative to zero. (Contributed by Mario Carneiro, 27-May-2016)

Ref Expression
Hypothesis leidd.1 φA
Assertion le0neg1d φA00A

Proof

Step Hyp Ref Expression
1 leidd.1 φA
2 le0neg1 AA00A
3 1 2 syl φA00A