Metamath Proof Explorer


Theorem renemnfd

Description: No real equals minus infinity. (Contributed by Mario Carneiro, 28-May-2016)

Ref Expression
Hypothesis rexrd.1 φA
Assertion renemnfd φA−∞

Proof

Step Hyp Ref Expression
1 rexrd.1 φA
2 renemnf AA−∞
3 1 2 syl φA−∞