Theorem sylan9ssr 3161

Description: A subclass transitivity deduction. (Contributed by NM, 27-Sep-2004.)

Hypotheses

Ref	Expression
sylan9ssr.1	⊢ (𝜑 → 𝐴 ⊆ 𝐵)
sylan9ssr.2	⊢ (𝜓 → 𝐵 ⊆ 𝐶)

Assertion

Ref	Expression
sylan9ssr	⊢ ((𝜓 ∧ 𝜑) → 𝐴 ⊆ 𝐶)

Proof of Theorem sylan9ssr

Step	Hyp	Ref	Expression
1		sylan9ssr.1	. . 3 ⊢ (𝜑 → 𝐴 ⊆ 𝐵)
2		sylan9ssr.2	. . 3 ⊢ (𝜓 → 𝐵 ⊆ 𝐶)
3	1, 2	sylan9ss 3160	. 2 ⊢ ((𝜑 ∧ 𝜓) → 𝐴 ⊆ 𝐶)
4	3	ancoms 266	1 ⊢ ((𝜓 ∧ 𝜑) → 𝐴 ⊆ 𝐶)

Syntax hints:   → wi 4   ∧ wa 103   ⊆ wss 3121

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-5 1440  ax-7 1441  ax-gen 1442  ax-ie1 1486  ax-ie2 1487  ax-8 1497  ax-11 1499  ax-4 1503  ax-17 1519  ax-i9 1523  ax-ial 1527  ax-i5r 1528  ax-ext 2152

This theorem depends on definitions:  df-bi 116  df-nf 1454  df-sb 1756  df-clab 2157  df-cleq 2163  df-clel 2166  df-in 3127  df-ss 3134

This theorem is referenced by:  intssuni2m  3855