Theorem pssv 4368

Description: Any non-universal class is a proper subclass of the universal class. Dual of 0pss 4366. (Contributed by NM, 17-May-1998.)

Assertion

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

Proof of Theorem pssv

Step	Hyp	Ref	Expression
1		ssv 3960	. 2 ⊢ 𝐴 ⊆ V
2		dfpss2 4041	. 2 ⊢ (𝐴 ⊊ V ↔ (𝐴 ⊆ V ∧ ¬ 𝐴 = V))
3	1, 2	mpbiran 721	1 ⊢ (𝐴 ⊊ V ↔ ¬ 𝐴 = V)

Syntax hints:  ¬ wn 3   ↔ wb 209   = wceq 1568  Vcvv 3453   ⊆ wss 3904   ⊊ wpss 3905

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1823  ax-4 1837  ax-5 1938  ax-6 1995  ax-7 2036  ax-8 2143  ax-9 2151  ax-ext 2733

This theorem depends on definitions:  df-bi 210  df-an 401  df-tru 1571  df-ex 1808  df-sb 2095  df-clab 2740  df-cleq 2753  df-clel 2836  df-ne 2957  df-v 3455  df-ss 3921  df-pss 3924

This theorem is referenced by: (None)