Nuprl Lemma : rcos-positive-before-half-pi

x:{x:ℝx ∈ [r0, π/2)} (r0 < rcos(x))


Proof




Definitions occuring in Statement :  halfpi: π/2 rcos: rcos(x) rcoint: [l, u) i-member: r ∈ I rless: x < y int-to-real: r(n) real: all: x:A. B[x] set: {x:A| B[x]}  natural_number: $n
Definitions unfolded in proof :  member: t ∈ T uall: [x:A]. B[x] all: x:A. B[x] sq_stable: SqStable(P) implies:  Q top: Top and: P ∧ Q exists: x:A. B[x] squash: T prop: so_lambda: λ2x.t[x] so_apply: x[s] guard: {T} uimplies: supposing a iff: ⇐⇒ Q rev_implies:  Q itermConstant: "const" req_int_terms: t1 ≡ t2 false: False not: ¬A uiff: uiff(P;Q) converges-to: lim n→∞.x[n] y sq_exists: x:{A| B[x]} nat: nat_plus: + rneq: x ≠ y or: P ∨ Q rless: x < y ge: i ≥  decidable: Dec(P) satisfiable_int_formula: satisfiable_int_formula(fmla) rleq: x ≤ y rnonneg: rnonneg(x) le: A ≤ B subtype_rel: A ⊆B real: rev_uimplies: rev_uimplies(P;Q) rge: x ≥ y
Lemmas referenced :  rcos-seq-converges-to-half-pi rcos-seq_wf nat_wf half-pi_wf halfpi_wf sq_stable__rless int-to-real_wf rcos_wf member_rcoint_lemma rcos-seq-positive set_wf real_wf i-member_wf rcoint_wf member_rccint_lemma rleq_wf converges-to_functionality req_weakening req_inversion halfpi-half-pi radd-preserves-rless rsub_wf rless_functionality radd_wf real_term_polynomial itermSubtract_wf itermAdd_wf itermVar_wf itermConstant_wf real_term_value_const_lemma real_term_value_sub_lemma real_term_value_add_lemma real_term_value_var_lemma req-iff-rsub-is-0 small-reciprocal-real rless_wf sq_stable__all le_wf rabs_wf rdiv_wf rless-int nat_properties nat_plus_properties decidable__lt satisfiable-full-omega-tt intformand_wf intformnot_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf sq_stable__rleq less_than'_wf nat_plus_wf squash_wf sq_stable__less_than decidable__le intformle_wf int_formula_prop_le_lemma rabs-difference-bound-rleq rleq_functionality_wrt_implies rleq_weakening_equal rleq_weakening rsub_functionality_wrt_rleq rleq_weakening_rless
Rules used in proof :  cut introduction extract_by_obid hypothesis sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaEquality sqequalHypSubstitution isectElimination thin hypothesisEquality because_Cache lambdaFormation setElimination rename dependent_functionElimination natural_numberEquality independent_functionElimination isect_memberEquality voidElimination voidEquality productElimination sqequalRule imageMemberEquality baseClosed imageElimination dependent_set_memberEquality independent_pairFormation productEquality independent_isectElimination computeAll int_eqEquality intEquality functionEquality inrFormation unionElimination dependent_pairFormation independent_pairEquality applyEquality minusEquality axiomEquality equalityTransitivity equalitySymmetry addEquality

Latex:
\mforall{}x:\{x:\mBbbR{}|  x  \mmember{}  [r0,  \mpi{}/2)\}  .  (r0  <  rcos(x))



Date html generated: 2017_10_04-PM-10_25_19
Last ObjectModification: 2017_07_28-AM-08_49_05

Theory : reals_2


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