Theorem clss2lem 44378

Description: The closure of a property is a superset of the closure of a less restrictive property. (Contributed by RP, 24-Jul-2020.)

Hypothesis

Ref	Expression
clss2lem.1	⊢ (𝜑 → (𝜒 → 𝜓))

Assertion

Ref	Expression
clss2lem	⊢ (𝜑 → ∩ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜓)} ⊆ ∩ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜒)})

Distinct variable group:   𝜑,𝑥

Allowed substitution hints:   𝜓(𝑥)   𝜒(𝑥)   𝑋(𝑥)

Proof of Theorem clss2lem

Step	Hyp	Ref	Expression
1		clss2lem.1	. . . . 5 ⊢ (𝜑 → (𝜒 → 𝜓))
2	1	adantld 496	. . . 4 ⊢ (𝜑 → ((𝑋 ⊆ 𝑥 ∧ 𝜒) → 𝜓))
3	2	alrimiv 1960	. . 3 ⊢ (𝜑 → ∀𝑥((𝑋 ⊆ 𝑥 ∧ 𝜒) → 𝜓))
4		pm5.3 583	. . . . 5 ⊢ (((𝑋 ⊆ 𝑥 ∧ 𝜒) → 𝜓) ↔ ((𝑋 ⊆ 𝑥 ∧ 𝜒) → (𝑋 ⊆ 𝑥 ∧ 𝜓)))
5	4	albii 1852	. . . 4 ⊢ (∀𝑥((𝑋 ⊆ 𝑥 ∧ 𝜒) → 𝜓) ↔ ∀𝑥((𝑋 ⊆ 𝑥 ∧ 𝜒) → (𝑋 ⊆ 𝑥 ∧ 𝜓)))
6		ss2ab 4018	. . . 4 ⊢ ({𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜒)} ⊆ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜓)} ↔ ∀𝑥((𝑋 ⊆ 𝑥 ∧ 𝜒) → (𝑋 ⊆ 𝑥 ∧ 𝜓)))
7	5, 6	bitr4i 281	. . 3 ⊢ (∀𝑥((𝑋 ⊆ 𝑥 ∧ 𝜒) → 𝜓) ↔ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜒)} ⊆ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜓)})
8	3, 7	sylib 221	. 2 ⊢ (𝜑 → {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜒)} ⊆ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜓)})
9		intss 4939	. 2 ⊢ ({𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜒)} ⊆ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜓)} → ∩ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜓)} ⊆ ∩ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜒)})
10	8, 9	syl 18	1 ⊢ (𝜑 → ∩ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜓)} ⊆ ∩ {𝑥 ∣ (𝑋 ⊆ 𝑥 ∧ 𝜒)})

This proof depends on syntax axioms:   → wi 4   ∧ wa 401  ∀wal 1568  {cab 2744   ⊆ wss 3908  ∩ cint 4917

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 2148  ax-9 2156  ax-10 2179  ax-11 2195  ax-12 2216  ax-ext 2738

This proof depends on definitions:  df-bi 210  df-an 402  df-or 862  df-ex 1813  df-nf 1817  df-sb 2100  df-clab 2745  df-cleq 2758  df-clel 2841  df-nfc 2915  df-ral 3083  df-ss 3925  df-int 4918

This theorem is used by: (None)