Nuprl Lemma : not-less-implies-equal

∀x,y:ℤ.  (x = y ∈ ℤ) supposing ((¬x < y) and (¬y < x))


Proof




Definitions occuring in Statement :  less_than: a < b,  uimplies: b supposing a,  all: ∀x:A. B[x],  not: ¬A,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  uimplies: b supposing a,  member: t ∈ T,  decidable: Dec(P),  or: P ∨ Q,  iff: P ⇐⇒ Q,  and: P ∧ Q,  not: ¬A,  rev_implies: P ⇐ Q,  implies: P ⇒ Q,  false: False,  prop: ℙ,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  subtype_rel: A ⊆r B,  top: Top,  le: A ≤ B,  less_than': less_than'(a;b),  true: True
Lemmas referenced :  decidable__int_equal,  false_wf,  not-equal-2,  not-lt-2,  add_functionality_wrt_le,  add-swap,  add-commutes,  le-add-cancel,  add-associates,  not_wf,  less_than_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  isect_memberFormation,  introduction,  cut,  lemma_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  hypothesisEquality,  hypothesis,  unionElimination,  independent_pairFormation,  voidElimination,  productElimination,  independent_functionElimination,  independent_isectElimination,  isectElimination,  addEquality,  natural_numberEquality,  sqequalRule,  applyEquality,  lambdaEquality,  isect_memberEquality,  voidEquality,  intEquality,  because_Cache,  axiomEquality,  equalityTransitivity,  equalitySymmetry

Latex:
\mforall{}x,y:\mBbbZ{}.    (x  =  y)  supposing  ((\mneg{}x  <  y)  and  (\mneg{}y  <  x))



Date html generated: 2016_05_13-PM-03_32_27
Last ObjectModification: 2015_12_26-AM-09_45_20

Theory : arithmetic


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