Metamath Proof Explorer


Theorem xnn0xrnemnf

Description: The extended nonnegative integers are extended reals without negative infinity. (Contributed by AV, 10-Dec-2020)

Ref Expression
Assertion xnn0xrnemnf A 0 * A * A −∞

Proof

Step Hyp Ref Expression
1 xnn0xr A 0 * A *
2 xnn0nemnf A 0 * A −∞
3 1 2 jca A 0 * A * A −∞