Theorem pssv 4361

Description: Any non-universal class is a proper subclass of the universal class. Dual of 0pss 4359. (Contributed by NM, 17-May-1998.)

Assertion

Ref	Expression
pssv	⊢ (𝐴 ⊊ V ↔ ¬ 𝐴 = V)

Proof of Theorem pssv

Step	Hyp	Ref	Expression
1		ssv 3954	. 2 ⊢ 𝐴 ⊆ V
2		dfpss2 4035	. 2 ⊢ (𝐴 ⊊ V ↔ (𝐴 ⊆ V ∧ ¬ 𝐴 = V))
3	1, 2	mpbiran 722	1 ⊢ (𝐴 ⊊ V ↔ ¬ 𝐴 = V)

This proof depends on syntax axioms:  ¬ wn 3   ↔ wb 209   = wceq 1570  Vcvv 3450   ⊆ wss 3898   ⊊ wpss 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-9 2155  ax-ext 2732

This proof depends on definitions:  df-bi 210  df-an 402  df-tru 1573  df-ex 1813  df-sb 2100  df-clab 2739  df-cleq 2752  df-clel 2835  df-ne 2956  df-v 3452  df-ss 3915  df-pss 3918

This theorem is used by: (None)