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* ) |