Nuprl Lemma : subtract-is-int-iff

∀[a,b:Base].  uiff(a - b ∈ ℤ;(a ∈ ℤ) ∧ (b ∈ ℤ))


Proof




Definitions occuring in Statement :  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  and: P ∧ Q,  member: t ∈ T,  subtract: n - m,  int: ℤ,  base: Base
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtract: n - m,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  prop: ℙ,  implies: P ⇒ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  minus-is-int-iff,  add-is-int-iff,  iff_weakening_uiff,  iff_transitivity,  uiff_wf,  base_wf,  equal-wf-base
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  sqequalRule,  sqequalHypSubstitution,  productElimination,  thin,  independent_pairEquality,  isect_memberEquality,  isectElimination,  hypothesisEquality,  axiomEquality,  equalityTransitivity,  hypothesis,  equalitySymmetry,  lemma_by_obid,  intEquality,  baseApply,  closedConclusion,  baseClosed,  because_Cache,  productEquality,  independent_pairFormation,  instantiate,  cumulativity,  addLevel,  independent_isectElimination,  independent_functionElimination,  lambdaFormation

Latex:
\mforall{}[a,b:Base].    uiff(a  -  b  \mmember{}  \mBbbZ{};(a  \mmember{}  \mBbbZ{})  \mwedge{}  (b  \mmember{}  \mBbbZ{}))



Date html generated: 2016_05_13-PM-03_28_37
Last ObjectModification: 2016_01_14-PM-06_42_07

Theory : arithmetic


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