Nuprl Lemma : imax-imin-absorption

∀[x,y:ℤ].  (imax(x;imin(x;y)) = x ∈ ℤ)


Proof




Definitions occuring in Statement :  imin: imin(a;b),  imax: imax(a;b),  uall: ∀[x:A]. B[x],  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  imin: imin(a;b),  imax: imax(a;b),  uimplies: b supposing a,  has-value: (a)↓,  all: ∀x:A. B[x],  implies: P ⇒ Q,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  uiff: uiff(P;Q),  and: P ∧ Q,  ifthenelse: if b then t else f fi ,  bfalse: ff,  exists: ∃x:A. B[x],  prop: ℙ,  or: P ∨ Q,  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  false: False,  not: ¬A
Lemmas referenced :  value-type-has-value,  int-value-type,  le_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_le_int,  eqff_to_assert,  equal_wf,  bool_cases_sqequal,  subtype_base_sq,  bool_subtype_base,  assert-bnot,  le_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  hypothesis,  intEquality,  sqequalRule,  sqequalHypSubstitution,  isect_memberEquality,  isectElimination,  thin,  hypothesisEquality,  axiomEquality,  because_Cache,  extract_by_obid,  independent_isectElimination,  callbyvalueReduce,  lambdaFormation,  unionElimination,  equalityElimination,  equalityTransitivity,  equalitySymmetry,  productElimination,  dependent_pairFormation,  promote_hyp,  dependent_functionElimination,  instantiate,  cumulativity,  independent_functionElimination,  voidElimination

Latex:
\mforall{}[x,y:\mBbbZ{}].    (imax(x;imin(x;y))  =  x)



Date html generated: 2017_04_14-AM-09_14_33
Last ObjectModification: 2017_02_27-PM-03_51_53

Theory : int_2


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