Nuprl Lemma : less-iff-le

∀x,y:ℤ.  uiff(x < y;(1 + x) ≤ y)


Proof




Definitions occuring in Statement :  less_than: a < b,  uiff: uiff(P;Q),  le: A ≤ B,  all: ∀x:A. B[x],  add: n + m,  natural_number: $n,  int: ℤ
Definitions unfolded in proof :  prop: ℙ,  uall: ∀[x:A]. B[x],  false: False,  implies: P ⇒ Q,  not: ¬A,  le: A ≤ B,  member: t ∈ T,  uimplies: b supposing a,  and: P ∧ Q,  uiff: uiff(P;Q),  all: ∀x:A. B[x],  rev_uimplies: rev_uimplies(P;Q),  subtype_rel: A ⊆r B,  squash: ↓T,  cand: A c∧ B,  less_than: a < b,  or: P ∨ Q,  true: True,  less_than': less_than'(a;b),  guard: {T},  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  top: Top,  bfalse: ff,  exists: ∃x:A. B[x],  sq_type: SQType(T),  bnot: ¬bb,  ifthenelse: if b then t else f fi ,  assert: ↑b,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q
Lemmas referenced :  le_wf,  less_than_wf,  less_than'_wf,  le-iff-less-or-equal,  int_subtype_base,  equal-wf-base,  lt_int_wf,  eqtt_to_assert,  assert_of_lt_int,  istype-top,  istype-void,  eqff_to_assert,  bool_subtype_base,  bool_cases_sqequal,  subtype_base_sq,  bool_wf,  iff_transitivity,  assert_wf,  bnot_wf,  not_wf,  iff_weakening_uiff,  assert_of_bnot,  istype-assert,  zero-add,  le_reflexive,  add_functionality_wrt_lt,  less_than_transitivity1
Rules used in proof :  intEquality,  equalitySymmetry,  equalityTransitivity,  axiomEquality,  hypothesis,  natural_numberEquality,  addEquality,  isectElimination,  extract_by_obid,  voidElimination,  hypothesisEquality,  dependent_functionElimination,  lambdaEquality,  independent_pairEquality,  thin,  productElimination,  sqequalHypSubstitution,  sqequalRule,  cut,  introduction,  isect_memberFormation,  independent_pairFormation,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution,  independent_isectElimination,  lessCases,  applyEquality,  closedConclusion,  baseApply,  baseClosed,  imageMemberEquality,  inlFormation,  inrFormation,  lessDiscrete,  Error :inhabitedIsType,  Error :lambdaFormation_alt,  unionElimination,  equalityElimination,  because_Cache,  Error :isect_memberFormation_alt,  axiomSqEquality,  Error :isect_memberEquality_alt,  Error :isectIsTypeImplies,  imageElimination,  independent_functionElimination,  Error :dependent_pairFormation_alt,  Error :equalityIsType4,  promote_hyp,  instantiate,  cumulativity,  Error :functionIsType,  Error :equalityIsType1

Latex:
\mforall{}x,y:\mBbbZ{}.    uiff(x  <  y;(1  +  x)  \mleq{}  y)



Date html generated: 2019_06_20-AM-11_23_03
Last ObjectModification: 2018_10_16-PM-02_47_37

Theory : arithmetic


Home Index