Theorem ssdf2 46155

Description: A sufficient condition for a subclass relationship. (Contributed by Glauco Siliprandi, 2-Jan-2022.)

Hypotheses

Ref	Expression
ssdf2.p	⊢ Ⅎ𝑥𝜑
ssdf2.a	⊢ Ⅎ𝑥𝐴
ssdf2.b	⊢ Ⅎ𝑥𝐵
ssdf2.x	⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 𝐵)

Assertion

Ref	Expression
ssdf2	⊢ (𝜑 → 𝐴 ⊆ 𝐵)

Proof of Theorem ssdf2

Step	Hyp	Ref	Expression
1		ssdf2.p	. 2 ⊢ Ⅎ𝑥𝜑
2		ssdf2.a	. 2 ⊢ Ⅎ𝑥𝐴
3		ssdf2.b	. 2 ⊢ Ⅎ𝑥𝐵
4		ssdf2.x	. . 3 ⊢ ((𝜑 ∧ 𝑥 ∈ 𝐴) → 𝑥 ∈ 𝐵)
5	4	ex 418	. 2 ⊢ (𝜑 → (𝑥 ∈ 𝐴 → 𝑥 ∈ 𝐵))
6	1, 2, 3, 5	ssrd 3936	1 ⊢ (𝜑 → 𝐴 ⊆ 𝐵)

This proof depends on syntax axioms:   → wi 4   ∧ wa 401  Ⅎwnf 1816   ∈ wcel 2145  Ⅎwnfc 2908   ⊆ wss 3899

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-8 2147  ax-11 2194  ax-12 2213

This proof depends on definitions:  df-bi 210  df-an 402  df-ex 1813  df-nf 1817  df-clel 2836  df-nfc 2910  df-ss 3916

This theorem is used by:  supminfxr2  46478  pimiooltgt  47719  sssmf  47747  fsupdm  47851  finfdm  47855