Nuprl Lemma : sqeq-copath4

[a,b,c,m:Top].
  x.if (x) < (m)  then if (x) < (m)  then a[x]  else b[x]  else c[x] ~ λx.if (x) < (m)  then a[x]  else c[x])


Proof




Definitions occuring in Statement :  uall: [x:A]. B[x] top: Top so_apply: x[s] less: if (a) < (b)  then c  else d lambda: λx.A[x] sqequal: t
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T assert: b ifthenelse: if then else fi  bnot: ¬bb guard: {T} sq_type: SQType(T) or: P ∨ Q exists: x:A. B[x] bfalse: ff prop: false: False not: ¬A squash: T true: True top: Top less_than': less_than'(a;b) less_than: a < b uimplies: supposing a uiff: uiff(P;Q) btrue: tt it: unit: Unit bool: 𝔹 implies:  Q all: x:A. B[x] and: P ∧ Q has-value: (a)↓
Lemmas referenced :  top_wf is-exception_wf has-value_wf_base assert-bnot bool_subtype_base subtype_base_sq bool_cases_sqequal equal_wf eqff_to_assert less_than_wf assert_of_lt_int eqtt_to_assert bool_wf lt_int_wf
Rules used in proof :  isect_memberEquality axiomSqEquality isect_memberFormation because_Cache sqleReflexivity hypothesis hypothesisEquality baseClosed closedConclusion baseApply isectElimination sqequalHypSubstitution extract_by_obid introduction sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution divergentSqle thin sqleRule cut sqequalSqle sqequalRule cumulativity instantiate dependent_functionElimination promote_hyp dependent_pairFormation independent_functionElimination imageElimination imageMemberEquality natural_numberEquality voidEquality voidElimination independent_pairFormation lessCases independent_isectElimination equalitySymmetry equalityTransitivity equalityElimination unionElimination lambdaFormation productElimination callbyvalueLess exceptionSqequal axiomSqleEquality lessExceptionCases exceptionLess

Latex:
\mforall{}[a,b,c,m:Top].
    (\mlambda{}x.if  (x)  <  (m)    then  if  (x)  <  (m)    then  a[x]    else  b[x]    else  c[x]  \msim{}  \mlambda{}x.if  (x)  <  (m)
                                                                                                                                                              then  a[x]
                                                                                                                                                              else  c[x])



Date html generated: 2019_06_20-PM-01_12_09
Last ObjectModification: 2019_01_02-PM-01_35_38

Theory : co-recursion-2


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