Theorem bnj1241 35227

Description: First-order logic and set theory. (Contributed by Jonathan Ben-Naim, 3-Jun-2011.) (New usage is discouraged.)

Hypotheses

Ref	Expression
bnj1241.1	⊢ (𝜑 → 𝐴 ⊆ 𝐵)
bnj1241.2	⊢ (𝜓 → 𝐶 = 𝐴)

Assertion

Ref	Expression
bnj1241	⊢ ((𝜑 ∧ 𝜓) → 𝐶 ⊆ 𝐵)

Proof of Theorem bnj1241

Step	Hyp	Ref	Expression
1		bnj1241.2	. . . 4 ⊢ (𝜓 → 𝐶 = 𝐴)
2	1	eqcomd 2772	. . 3 ⊢ (𝜓 → 𝐴 = 𝐶)
3	2	adantl 487	. 2 ⊢ ((𝜑 ∧ 𝜓) → 𝐴 = 𝐶)
4		bnj1241.1	. . 3 ⊢ (𝜑 → 𝐴 ⊆ 𝐵)
5	4	adantr 486	. 2 ⊢ ((𝜑 ∧ 𝜓) → 𝐴 ⊆ 𝐵)
6	3, 5	eqsstrrd 3975	1 ⊢ ((𝜑 ∧ 𝜓) → 𝐶 ⊆ 𝐵)

This proof depends on syntax axioms:   → wi 4   ∧ wa 401   = wceq 1570   ⊆ wss 3908

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-9 2156  ax-ext 2738

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813  df-cleq 2758  df-ss 3925

This theorem is used by:  bnj1245  35434  bnj1311  35444