Nuprl Lemma : equal-bnot

∀[x,y:𝔹].  uiff(x = ¬by;¬x = y)


Proof




Definitions occuring in Statement :  bnot: ¬bb,  bool: 𝔹,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  not: ¬A,  equal: s = t ∈ T
Definitions unfolded in proof :  member: t ∈ T,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uall: ∀[x:A]. B[x],  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  not: ¬A,  false: False,  prop: ℙ,  assert: ↑b,  bfalse: ff,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  decidable: Dec(P)
Lemmas referenced :  eqtt_to_assert,  btrue_neq_bfalse,  equal-wf-T-base,  bool_wf,  iff_imp_equal_bool,  bfalse_wf,  assert_elim,  assert_wf,  false_wf,  not_wf,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  assert_witness,  assert_of_bnot,  bnot_wf,  uiff_wf,  iff_weakening_uiff,  decidable__assert
Rules used in proof :  cut,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  hypothesisEquality,  thin,  because_Cache,  lambdaFormation,  sqequalHypSubstitution,  unionElimination,  equalityElimination,  introduction,  extract_by_obid,  isectElimination,  hypothesis,  productElimination,  independent_isectElimination,  sqequalRule,  independent_pairFormation,  isect_memberFormation,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  voidElimination,  baseClosed,  lambdaEquality,  dependent_functionElimination,  addLevel,  levelHypothesis,  dependent_pairFormation,  promote_hyp,  instantiate,  cumulativity,  functionEquality,  independent_pairEquality,  isect_memberEquality,  axiomEquality

Latex:
\mforall{}[x,y:\mBbbB{}].    uiff(x  =  \mneg{}\msubb{}y;\mneg{}x  =  y)



Date html generated: 2017_10_01-AM-09_12_43
Last ObjectModification: 2017_07_26-PM-04_48_20

Theory : general


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