Nuprl Lemma : less-iff-positive

∀[x,y:ℤ].  uiff(x < y;0 < y - x)


Proof




Definitions occuring in Statement :  less_than: a < b,  uiff: uiff(P;Q),  uall: ∀[x:A]. B[x],  subtract: n - m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  member: t ∈ T,  prop: ℙ,  uall: ∀[x:A]. B[x],  or: P ∨ Q,  all: ∀x:A. B[x],  implies: P ⇒ Q,  subtract: n - m,  top: Top
Lemmas referenced :  less_than_wf,  subtract_wf,  member-less_than,  add-monotonic,  add-inverse,  zero-add,  add-associates,  minus-one-mul,  add-swap,  add-commutes,  add-mul-special,  zero-mul
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  independent_pairFormation,  isect_memberFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  natural_numberEquality,  because_Cache,  intEquality,  sqequalRule,  productElimination,  independent_pairEquality,  isect_memberEquality,  independent_isectElimination,  equalityTransitivity,  equalitySymmetry,  minusEquality,  inlFormation,  dependent_functionElimination,  independent_functionElimination,  voidElimination,  voidEquality,  multiplyEquality

Latex:
\mforall{}[x,y:\mBbbZ{}].    uiff(x  <  y;0  <  y  -  x)



Date html generated: 2019_06_20-AM-11_22_32
Last ObjectModification: 2018_08_17-PM-00_02_42

Theory : arithmetic


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