Nuprl Lemma : rless-cases

∀x,y:ℝ.  ((x < y) ⇒ (∀z:ℝ. ((x < z) ∨ (z < y))))


Proof




Definitions occuring in Statement :  rless: x < y,  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  or: P ∨ Q
Definitions unfolded in proof :  member: t ∈ T,  rless-cases-proof,  rless-iff8,  decidable__lt,  decidable__squash,  uall: ∀[x:A]. B[x],  so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]),  so_apply: x[s1;s2;s3;s4],  top: Top,  uimplies: b supposing a,  strict4: strict4(F),  and: P ∧ Q,  all: ∀x:A. B[x],  implies: P ⇒ Q,  has-value: (a)↓,  prop: ℙ,  guard: {T},  or: P ∨ Q,  squash: ↓T,  so_lambda: λ2x y.t[x; y],  so_apply: x[s1;s2],  so_lambda: λ2x.t[x],  so_apply: x[s],  decidable_functionality,  iff_preserves_decidability,  decidable__and,  decidable__less_than',  rless-case: rless-case(x;y;n;z)
Lemmas referenced :  rless-cases-proof,  lifting-strict-spread,  has-value_wf_base,  base_wf,  is-exception_wf,  top_wf,  equal_wf,  lifting-strict-decide,  lifting-strict-less,  rless-iff8,  decidable__lt,  decidable__squash,  decidable_functionality,  iff_preserves_decidability,  decidable__and,  decidable__less_than'
Rules used in proof :  introduction,  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  cut,  instantiate,  extract_by_obid,  hypothesis,  sqequalRule,  thin,  sqequalHypSubstitution,  isectElimination,  baseClosed,  isect_memberEquality,  voidElimination,  voidEquality,  independent_isectElimination,  independent_pairFormation,  lambdaFormation,  callbyvalueApply,  baseApply,  closedConclusion,  hypothesisEquality,  applyExceptionCases,  inrFormation,  imageMemberEquality,  imageElimination,  exceptionSqequal,  inlFormation,  callbyvalueDecide,  equalityTransitivity,  equalitySymmetry,  unionEquality,  unionElimination,  sqleReflexivity,  dependent_functionElimination,  independent_functionElimination,  decideExceptionCases,  because_Cache

Latex:
\mforall{}x,y:\mBbbR{}.    ((x  <  y)  {}\mRightarrow{}  (\mforall{}z:\mBbbR{}.  ((x  <  z)  \mvee{}  (z  <  y))))



Date html generated: 2017_10_03-AM-08_46_36
Last ObjectModification: 2017_07_28-AM-07_32_44

Theory : reals


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