Nuprl Lemma : sqeq-copath1

∀[a,b,n:Top].  (λm.if (m) < (n - 1)  then a[m]  else b[m] ~ λm.if (m + 1) < (n)  then a[m]  else b[m])


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],  subtract: n - m,  add: n + m,  natural_number: $n,  sqequal: s ~ t
Definitions unfolded in proof :  member: t ∈ T,  uall: ∀[x:A]. B[x],  and: P ∧ Q,  has-value: (a)↓,  le: A ≤ B,  subtype_rel: A ⊆r B,  assert: ↑b,  ifthenelse: if b then t else f fi ,  bnot: ¬bb,  guard: {T},  sq_type: SQType(T),  or: P ∨ Q,  exists: ∃x:A. B[x],  bfalse: ff,  prop: ℙ,  false: False,  not: ¬A,  squash: ↓T,  true: True,  top: Top,  less_than': less_than'(a;b),  less_than: a < b,  uiff: uiff(P;Q),  btrue: tt,  it: ⋅,  unit: Unit,  bool: 𝔹,  implies: P ⇒ Q,  all: ∀x:A. B[x],  subtract: n - m,  uimplies: b supposing a,  is-exception: is-exception(t)
Lemmas referenced :  top_wf,  is-exception_wf,  has-value_wf_base,  minus-minus,  le-add-cancel,  zero-add,  add_functionality_wrt_le,  add-commutes,  minus-add,  less-iff-le,  minus-one-mul-top,  add-swap,  minus-one-mul,  base_wf,  add-associates,  condition-implies-le,  not-lt-2,  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,  int-value-type,  value-type-has-value,  exception-not-bottom,  bottom_diverge,  exception-not-value_1,  add-is-int-iff,  subtract_wf
Rules used in proof :  because_Cache,  isect_memberEquality,  axiomSqEquality,  sqleReflexivity,  hypothesis,  hypothesisEquality,  baseClosed,  closedConclusion,  baseApply,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  divergentSqle,  thin,  sqleRule,  sqequalSqle,  sqequalRule,  cut,  introduction,  isect_memberFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  productElimination,  callbyvalueLess,  minusEquality,  lambdaEquality,  applyEquality,  cumulativity,  instantiate,  dependent_functionElimination,  promote_hyp,  dependent_pairFormation,  addEquality,  independent_functionElimination,  imageElimination,  imageMemberEquality,  natural_numberEquality,  voidEquality,  voidElimination,  independent_pairFormation,  lessCases,  equalityElimination,  unionElimination,  lambdaFormation,  callbyvalueAdd,  equalitySymmetry,  equalityTransitivity,  independent_isectElimination,  intEquality,  exceptionSqequal,  axiomSqleEquality,  lessExceptionCases,  exceptionLess,  addExceptionCases

Latex:
\mforall{}[a,b,n:Top].
    (\mlambda{}m.if  (m)  <  (n  -  1)    then  a[m]    else  b[m]  \msim{}  \mlambda{}m.if  (m  +  1)  <  (n)    then  a[m]    else  b[m])



Date html generated: 2019_06_20-PM-01_11_52
Last ObjectModification: 2019_01_02-PM-01_35_32

Theory : co-recursion-2


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