Nuprl Lemma : sqeq-copath2

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


Proof




Definitions occuring in Statement :  uall: ∀[x:A]. B[x],  top: Top,  int_eq: if a=b then c else d,  subtract: n - m,  add: n + m,  natural_number: $n,  sqequal: s ~ t
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  true: True,  less_than': less_than'(a;b),  le: A ≤ B,  top: Top,  subtype_rel: A ⊆r B,  subtract: n - m,  nequal: a ≠ b ∈ T ,  not: ¬A,  false: False,  assert: ↑b,  ifthenelse: if b then t else f fi ,  bnot: ¬bb,  guard: {T},  sq_type: SQType(T),  or: P ∨ Q,  prop: ℙ,  exists: ∃x:A. B[x],  bfalse: ff,  uiff: uiff(P;Q),  btrue: tt,  it: ⋅,  unit: Unit,  bool: 𝔹,  implies: P ⇒ Q,  all: ∀x:A. B[x],  uimplies: b supposing a,  and: P ∧ Q,  has-value: (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,  le_antisymmetry_iff,  minus-one-mul-top,  add-swap,  minus-one-mul,  minus-add,  base_wf,  add-associates,  condition-implies-le,  not-equal-2,  add-is-int-iff,  neg_assert_of_eq_int,  assert-bnot,  bool_subtype_base,  subtype_base_sq,  bool_cases_sqequal,  equal_wf,  eqff_to_assert,  subtract_wf,  assert_of_eq_int,  eqtt_to_assert,  bool_wf,  eq_int_wf,  int-value-type,  value-type-has-value,  exception-not-bottom,  bottom_diverge,  exception-not-value_1
Rules used in proof :  isect_memberEquality,  axiomSqEquality,  isect_memberFormation,  because_Cache,  sqleReflexivity,  hypothesis,  hypothesisEquality,  baseClosed,  closedConclusion,  baseApply,  sqequalRule,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  divergentSqle,  thin,  sqleRule,  cut,  sqequalSqle,  natural_numberEquality,  voidEquality,  lambdaEquality,  applyEquality,  minusEquality,  addEquality,  int_eqReduceFalseSq,  voidElimination,  independent_functionElimination,  cumulativity,  instantiate,  dependent_functionElimination,  promote_hyp,  dependent_pairFormation,  int_eqReduceTrueSq,  equalityElimination,  unionElimination,  lambdaFormation,  callbyvalueAdd,  equalitySymmetry,  equalityTransitivity,  independent_isectElimination,  intEquality,  productElimination,  callbyvalueIntEq,  exceptionSqequal,  axiomSqleEquality,  int_eqExceptionCases,  exceptionInteq,  addExceptionCases

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



Date html generated: 2019_06_20-PM-01_11_59
Last ObjectModification: 2019_01_02-PM-01_35_34

Theory : co-recursion-2


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