Nuprl Lemma : rless-cases1

∀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 :  all: ∀x:A. B[x],  implies: P ⇒ Q,  member: t ∈ T,  uall: ∀[x:A]. B[x],  uimplies: b supposing a,  itermConstant: "const",  req_int_terms: t1 ≡ t2,  false: False,  not: ¬A,  top: Top,  uiff: uiff(P;Q),  and: P ∧ Q,  prop: ℙ,  guard: {T},  or: P ∨ Q,  rsub: x - y,  iff: P ⇐⇒ Q
Lemmas referenced :  radd-positive-implies,  rsub_wf,  rless-implies-rless,  int-to-real_wf,  radd_wf,  real_term_polynomial,  itermSubtract_wf,  itermVar_wf,  itermAdd_wf,  itermConstant_wf,  real_term_value_const_lemma,  real_term_value_sub_lemma,  real_term_value_var_lemma,  real_term_value_add_lemma,  req-iff-rsub-is-0,  real_wf,  rless_wf,  radd-ac,  radd-rminus-both,  radd-preserves-rless,  rminus_wf,  rless_functionality,  radd_comm,  radd_functionality,  req_weakening,  radd-rminus-assoc,  radd-zero-both
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  dependent_functionElimination,  thin,  isectElimination,  hypothesisEquality,  hypothesis,  independent_functionElimination,  natural_numberEquality,  independent_isectElimination,  sqequalRule,  computeAll,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  productElimination,  inrFormation,  lemma_by_obid,  inlFormation,  unionElimination,  promote_hyp

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



Date html generated: 2017_10_03-AM-08_39_44
Last ObjectModification: 2017_07_28-AM-07_30_53

Theory : reals


Home Index