Nuprl Lemma : ifthenelse-false-left

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


Proof




Definitions occuring in Statement :  assert: b ifthenelse: if then else fi  bool: 𝔹 uall: [x:A]. B[x] prop: all: x:A. B[x] iff: ⇐⇒ Q not: ¬A and: P ∧ Q false: False
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T implies:  Q bool: 𝔹 unit: Unit it: btrue: tt uall: [x:A]. B[x] uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a ifthenelse: if then else fi  assert: b iff: ⇐⇒ Q false: False prop: rev_implies:  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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