Theorem daraptiALT 2714

Description: Alternate proof of darapti 2713, shorter but using more axioms. See comment of dariiALT 2695. (Contributed by David A. Wheeler, 27-Aug-2016.) (Proof modification is discouraged.) (New usage is discouraged.)

Hypotheses

Ref	Expression
darapti.maj	⊢ ∀𝑥(𝜑 → 𝜓)
darapti.min	⊢ ∀𝑥(𝜑 → 𝜒)
darapti.e	⊢ ∃𝑥𝜑

Assertion

Ref	Expression
daraptiALT	⊢ ∃𝑥(𝜒 ∧ 𝜓)

Proof of Theorem daraptiALT

Step	Hyp	Ref	Expression
1		darapti.e	. 2 ⊢ ∃𝑥𝜑
2		darapti.min	. . . 4 ⊢ ∀𝑥(𝜑 → 𝜒)
3	2	spi 2223	. . 3 ⊢ (𝜑 → 𝜒)
4		darapti.maj	. . . 4 ⊢ ∀𝑥(𝜑 → 𝜓)
5	4	spi 2223	. . 3 ⊢ (𝜑 → 𝜓)
6	3, 5	jca 521	. 2 ⊢ (𝜑 → (𝜒 ∧ 𝜓))
7	1, 6	eximii 1870	1 ⊢ ∃𝑥(𝜒 ∧ 𝜓)

This proof depends on syntax axioms:   → wi 4   ∧ wa 401  ∀wal 1568  ∃wex 1812

This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1828  ax-4 1842  ax-5 1943  ax-6 2000  ax-7 2041  ax-12 2216

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813

This theorem is used by: (None)