Nuprl Lemma : psub_antisymmetry

∀[P,Q:formula()].  (P = Q ∈ formula()) supposing (Q ⊆ P and P ⊆ Q)


Proof




Definitions occuring in Statement :  psub: a ⊆ b,  formula: formula(),  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  uimplies: b supposing a,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q,  less_than: a < b,  squash: ↓T,  and: P ∧ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  prop: ℙ
Lemmas referenced :  formula_wf,  psub_wf,  int_formula_prop_wf,  int_term_value_var_lemma,  int_formula_prop_less_lemma,  int_formula_prop_and_lemma,  itermVar_wf,  intformless_wf,  intformand_wf,  satisfiable-full-omega-tt,  prank-psub
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  lemma_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  independent_functionElimination,  hypothesis,  because_Cache,  unionElimination,  equalitySymmetry,  imageElimination,  productElimination,  isectElimination,  natural_numberEquality,  independent_isectElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  sqequalRule,  independent_pairFormation,  computeAll,  axiomEquality,  equalityTransitivity

Latex:
\mforall{}[P,Q:formula()].    (P  =  Q)  supposing  (Q  \msubseteq{}  P  and  P  \msubseteq{}  Q)



Date html generated: 2016_05_15-PM-07_14_25
Last ObjectModification: 2016_01_16-AM-09_44_01

Theory : general


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