Nuprl Lemma : rcos-is-1-iff

x:ℝ(rcos(x) r1 ⇐⇒ ∃n:ℤ(x * π))


Proof




Definitions occuring in Statement :  pi: π rcos: rcos(x) int-rmul: k1 a req: y int-to-real: r(n) real: all: x:A. B[x] exists: x:A. B[x] iff: ⇐⇒ Q multiply: m natural_number: $n int:
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q uall: [x:A]. B[x] member: t ∈ T nat: false: False ge: i ≥  uimplies: supposing a not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] top: Top and: P ∧ Q prop: rleq: x ≤ y rnonneg: rnonneg(x) le: A ≤ B iff: ⇐⇒ Q rev_implies:  Q uiff: uiff(P;Q) req_int_terms: t1 ≡ t2 true: True rev_uimplies: rev_uimplies(P;Q) squash: T guard: {T} rge: x ≥ y rless: x < y sq_exists: x:A [B[x]] nat_plus: + decidable: Dec(P) or: P ∨ Q less_than: a < b less_than': less_than'(a;b) int-to-real: r(n) int-rmul: k1 a pi: π halfpi: π/2 divide: n ÷ m cubic_converge: cubic_converge(b;m) ifthenelse: if then else fi  le_int: i ≤j bnot: ¬bb lt_int: i <j bfalse: ff btrue: tt fastpi: fastpi(n) primrec: primrec(n;b;c) primtailrec: primtailrec(n;i;b;f) subtype_rel: A ⊆B real: rneq: x ≠ y rdiv: (x/y) so_lambda: λ2x.t[x] so_apply: x[s] rat_term_to_real: rat_term_to_real(f;t) rtermMultiply: left "*" right rat_term_ind: rat_term_ind rtermVar: rtermVar(var) rtermDivide: num "/" denom pi1: fst(t) pi2: snd(t)
Lemmas referenced :  nat_properties full-omega-unsat intformand_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf istype-int int_formula_prop_and_lemma istype-void int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf ge_wf istype-less_than le_witness_for_triv subtract-1-ge-0 istype-nat req_wf rcos_wf int-to-real_wf real_wf rcos-1-implies-at-least-2pi rless_wf rmul_wf int-rmul_wf pi_wf itermSubtract_wf itermMultiply_wf rleq_wf radd_wf itermAdd_wf rless_functionality req_weakening iff_weakening_uiff rleq_functionality req_transitivity rmul_functionality req_inversion radd-int req-iff-rsub-is-0 real_polynomial_null real_term_value_sub_lemma real_term_value_mul_lemma real_term_value_var_lemma real_term_value_const_lemma real_term_value_add_lemma rcos-shift-2n-pi rsub_wf rcos_functionality rminus_wf itermMinus_wf req_functionality squash_wf true_wf rminus-int real_term_value_minus_lemma rless-implies-rless radd-preserves-rleq rleq_weakening_equal rleq_functionality_wrt_implies rabs_wf rcos-is-1 rcos-rabs decidable__lt intformnot_wf int_formula_prop_not_lemma rleq_weakening_rless rmul_preserves_rless rdiv_wf rmul_preserves_rleq rinv_wf2 rless_transitivity1 rleq_weakening rabs-of-nonneg rabs-rdiv rdiv_functionality rmul-rinv3 r-archimedean-rabs-ext subtract_wf primrec-wf2 rleq_antisymmetry zero-rleq-rabs rabs-is-zero rless-cases rless-int int_term_value_subtract_lemma nat_plus_properties decidable__le istype-le subtract-add-cancel rabs-of-nonpos not-rless rless_transitivity2 rmul_preserves_req rminus-as-rmul rless_irreflexivity assert-rat-term-eq2 rtermVar_wf rtermMultiply_wf rtermDivide_wf int-rmul-req rmul-int
Rules used in proof :  cut sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt introduction extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis setElimination rename intWeakElimination natural_numberEquality independent_isectElimination approximateComputation independent_functionElimination dependent_pairFormation_alt lambdaEquality_alt int_eqEquality dependent_functionElimination isect_memberEquality_alt voidElimination sqequalRule independent_pairFormation universeIsType productElimination equalityTransitivity equalitySymmetry functionIsTypeImplies inhabitedIsType dependent_set_memberEquality_alt because_Cache addEquality minusEquality applyEquality imageElimination imageMemberEquality baseClosed productIsType multiplyEquality dependent_set_memberFormation_alt unionElimination closedConclusion inrFormation_alt functionIsType equalityIstype setIsType instantiate functionEquality productEquality intEquality inlFormation_alt

Latex:
\mforall{}x:\mBbbR{}.  (rcos(x)  =  r1  \mLeftarrow{}{}\mRightarrow{}  \mexists{}n:\mBbbZ{}.  (x  =  2  *  n  *  \mpi{}))



Date html generated: 2019_10_31-AM-06_06_39
Last ObjectModification: 2019_05_17-PM-03_51_07

Theory : reals_2


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