Theorem efald2 38762

Description: A proof by contradiction. (Contributed by Giovanni Mascellani, 15-Sep-2017.)

Hypothesis

Ref	Expression
efald2.1	⊢ (¬ 𝜑 → ⊥)

Assertion

Ref	Expression
efald2	⊢ 𝜑

Proof of Theorem efald2

Step	Hyp	Ref	Expression
1		efald2.1	. . . 4 ⊢ (¬ 𝜑 → ⊥)
2	1	adantl 487	. . 3 ⊢ ((⊤ ∧ ¬ 𝜑) → ⊥)
3	2	efald 1591	. 2 ⊢ (⊤ → 𝜑)
4	3	mptru 1577	1 ⊢ 𝜑

This proof depends on syntax axioms:  ¬ wn 3   → wi 4  ⊤wtru 1571  ⊥wfal 1582

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8

This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-fal 1583

This theorem is used by:  mpobi123f  38844  mptbi12f  38848  ac6s6  38854