Nuprl Lemma : rsin-first-req-1

∀x:ℝ. ((r0 ≤ x) ⇒ (rsin(x) = r1) ⇒ (π/2 ≤ x))


Proof




Definitions occuring in Statement :  halfpi: π/2,  rsin: rsin(x),  rleq: x ≤ y,  req: x = y,  int-to-real: r(n),  real: ℝ,  all: ∀x:A. B[x],  implies: P ⇒ Q,  natural_number: $n
Definitions unfolded in proof :  all: ∀x:A. B[x],  implies: P ⇒ Q,  uall: ∀[x:A]. B[x],  member: t ∈ T,  uiff: uiff(P;Q),  and: P ∧ Q,  uimplies: b supposing a,  not: ¬A,  top: Top,  prop: ℙ,  nat: ℕ,  le: A ≤ B,  less_than': less_than'(a;b),  false: False,  true: True,  squash: ↓T,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  or: P ∨ Q,  cand: A c∧ B,  guard: {T}
Lemmas referenced :  rleq-iff-not-rless,  halfpi_wf,  rcos-positive-before-half-pi,  member_rcoint_lemma,  rleq_wf,  int-to-real_wf,  rless_wf,  req_wf,  rsin_wf,  real_wf,  rsin-rcos-pythag,  radd_wf,  rnexp_wf,  false_wf,  le_wf,  rcos_wf,  rmul_wf,  radd-preserves-req,  rminus_wf,  req_functionality,  radd_functionality,  rnexp2,  req_transitivity,  rmul_functionality,  req_weakening,  uiff_transitivity,  rmul-int,  uiff_transitivity3,  squash_wf,  true_wf,  rminus-int,  radd-int,  radd-assoc,  radd-zero-both,  rmul-is-positive,  rless_transitivity1,  rleq_weakening,  rless_irreflexivity
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  productElimination,  independent_isectElimination,  dependent_functionElimination,  sqequalRule,  isect_memberEquality,  voidElimination,  voidEquality,  dependent_set_memberEquality,  independent_pairFormation,  productEquality,  natural_numberEquality,  because_Cache,  multiplyEquality,  minusEquality,  addEquality,  independent_functionElimination,  applyEquality,  lambdaEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  imageMemberEquality,  baseClosed,  inlFormation

Latex:
\mforall{}x:\mBbbR{}.  ((r0  \mleq{}  x)  {}\mRightarrow{}  (rsin(x)  =  r1)  {}\mRightarrow{}  (\mpi{}/2  \mleq{}  x))



Date html generated: 2016_10_26-PM-00_24_04
Last ObjectModification: 2016_09_12-PM-05_43_27

Theory : reals_2


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