Nuprl Lemma : psub_antisymmetry

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


Proof




Definitions occuring in Statement :  psub: a ⊆ b formula: formula() uimplies: supposing a uall: [x:A]. B[x] equal: t ∈ T
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uimplies: supposing a all: x:A. B[x] implies:  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:
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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