Nuprl Lemma : ifthenelse-false-left

∀b:𝔹. ∀[q:ℙ]. (if b then False else q fi  ⇐⇒ (¬↑b) ∧ q)


Proof




Definitions occuring in Statement :  assert: ↑b,  ifthenelse: if b then t else f fi ,  bool: 𝔹,  uall: ∀[x:A]. B[x],  prop: ℙ,  all: ∀x:A. B[x],  iff: P ⇐⇒ Q,  not: ¬A,  and: P ∧ Q,  false: False
Definitions unfolded in proof :  all: ∀x:A. B[x],  member: t ∈ T,  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,  ifthenelse: if b then t else f fi ,  assert: ↑b,  iff: P ⇐⇒ Q,  false: False,  prop: ℙ,  rev_implies: P ⇐ Q,  not: ¬A,  true: True,  bfalse: ff,  exists: ∃x:A. B[x],  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb
Lemmas referenced :  bool_wf,  eqtt_to_assert,  false_wf,  not_wf,  true_wf,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  hypothesisEquality,  thin,  introduction,  extract_by_obid,  hypothesis,  sqequalHypSubstitution,  unionElimination,  equalityElimination,  isectElimination,  productElimination,  independent_isectElimination,  sqequalRule,  isect_memberFormation,  independent_pairFormation,  voidElimination,  independent_functionElimination,  natural_numberEquality,  productEquality,  cumulativity,  universeEquality,  dependent_pairFormation,  promote_hyp,  dependent_functionElimination,  instantiate,  equalityTransitivity,  equalitySymmetry,  because_Cache

Latex:
\mforall{}b:\mBbbB{}.  \mforall{}[q:\mBbbP{}].  (if  b  then  False  else  q  fi    \mLeftarrow{}{}\mRightarrow{}  (\mneg{}\muparrow{}b)  \mwedge{}  q)



Date html generated: 2017_04_14-AM-07_32_09
Last ObjectModification: 2017_02_27-PM-03_00_03

Theory : bool_1


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