Database
REAL AND COMPLEX NUMBERS
Order sets
Infinity and the extended real number system (cont.)
xrltled
Metamath Proof Explorer
Description: 'Less than' implies 'less than or equal to' for extended reals.
Deduction form of xrltle . (Contributed by Glauco Siliprandi , 11-Dec-2019)
Ref
Expression
Hypotheses
xrltled.a
⊢ ( 𝜑 → 𝐴 ∈ ℝ* )
xrltled.b
⊢ ( 𝜑 → 𝐵 ∈ ℝ* )
xrltled.altb
⊢ ( 𝜑 → 𝐴 < 𝐵 )
Assertion
xrltled
⊢ ( 𝜑 → 𝐴 ≤ 𝐵 )
Proof
Step
Hyp
Ref
Expression
1
xrltled.a
⊢ ( 𝜑 → 𝐴 ∈ ℝ* )
2
xrltled.b
⊢ ( 𝜑 → 𝐵 ∈ ℝ* )
3
xrltled.altb
⊢ ( 𝜑 → 𝐴 < 𝐵 )
4
xrltle
⊢ ( ( 𝐴 ∈ ℝ* ∧ 𝐵 ∈ ℝ* ) → ( 𝐴 < 𝐵 → 𝐴 ≤ 𝐵 ) )
5
1 2 4
syl2anc
⊢ ( 𝜑 → ( 𝐴 < 𝐵 → 𝐴 ≤ 𝐵 ) )
6
3 5
mpd
⊢ ( 𝜑 → 𝐴 ≤ 𝐵 )