Description: "Less than or equal to" is a relation on extended reals. (Contributed by Mario Carneiro, 28-Apr-2015)
Ref | Expression | ||
---|---|---|---|
Assertion | lerelxr | ⊢ ≤ ⊆ ( ℝ* × ℝ* ) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | df-le | ⊢ ≤ = ( ( ℝ* × ℝ* ) ∖ ◡ < ) | |
2 | difss | ⊢ ( ( ℝ* × ℝ* ) ∖ ◡ < ) ⊆ ( ℝ* × ℝ* ) | |
3 | 1 2 | eqsstri | ⊢ ≤ ⊆ ( ℝ* × ℝ* ) |