Theorem syl23anc 1189

Description: Syllogism combined with contraction. (Contributed by NM, 11-Mar-2012.)

Hypotheses

Ref	Expression
sylXanc.1	⊢ (φ → ψ)
sylXanc.2	⊢ (φ → χ)
sylXanc.3	⊢ (φ → θ)
sylXanc.4	⊢ (φ → τ)
sylXanc.5	⊢ (φ → η)
syl23anc.6	⊢ (((ψ ∧ χ) ∧ (θ ∧ τ ∧ η)) → ζ)

Assertion

Ref	Expression
syl23anc	⊢ (φ → ζ)

Proof of Theorem syl23anc

Step	Hyp	Ref	Expression
1		sylXanc.1	. . 3 ⊢ (φ → ψ)
2		sylXanc.2	. . 3 ⊢ (φ → χ)
3	1, 2	jca 518	. 2 ⊢ (φ → (ψ ∧ χ))
4		sylXanc.3	. 2 ⊢ (φ → θ)
5		sylXanc.4	. 2 ⊢ (φ → τ)
6		sylXanc.5	. 2 ⊢ (φ → η)
7		syl23anc.6	. 2 ⊢ (((ψ ∧ χ) ∧ (θ ∧ τ ∧ η)) → ζ)
8	3, 4, 5, 6, 7	syl13anc 1184	1 ⊢ (φ → ζ)

This proof depends on syntax axioms:   → wi 4   ∧ wa 358   ∧ w3a 934

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

This proof depends on definitions:  df-bi 177  df-an 360  df-3an 936

This theorem is used by: (None)