Nuprl Lemma : DAlembert-equation-lemma

f,g:ℝ ⟶ ℝ.
  ((∀x,y:ℝ.  ((x y)  (f(x) f(y))))
   (∀x,y:ℝ.  ((x y)  (g(x) g(y))))
   ((∀x:ℝ(f(-(x)) f(x)))
     ∧ (∀n:ℤ. ∀y:ℝ.  (f(r(n 1) y) ((r(2) f(y) f(r(n) y)) f(r(n 1) y))))
     ∧ (∀t:ℝ((f((t/r(2))) f((t/r(2)))) (f(t) r1/r(2)))))
   ((∀x:ℝ(g(-(x)) g(x)))
     ∧ (∀n:ℤ. ∀y:ℝ.  (g(r(n 1) y) ((r(2) g(y) g(r(n) y)) g(r(n 1) y))))
     ∧ (∀t:ℝ((g((t/r(2))) g((t/r(2)))) (g(t) r1/r(2)))))
   (f(r0) g(r0))
   (∀a:ℝ
        ((r0 < a)
         (f(a) g(a))
         (∀x:{x:ℝx ∈ [-(a), a]} (r0 < f(x)))
         (∀x:{x:ℝx ∈ [-(a), a]} (r0 < g(x)))
         (∀x:ℝ(f(x) g(x))))))


Proof




Definitions occuring in Statement :  rfun-ap: f(x) rccint: [l, u] i-member: r ∈ I rdiv: (x/y) rless: x < y rsub: y req: y rmul: b rminus: -(x) radd: b int-to-real: r(n) real: all: x:A. B[x] implies:  Q and: P ∧ Q set: {x:A| B[x]}  function: x:A ⟶ B[x] subtract: m add: m natural_number: $n int:
Definitions unfolded in proof :  r-ap: f(x) rfun: I ⟶ℝ riiint: (-∞, ∞) i-member: r ∈ I lelt: i ≤ j < k int_seg: {i..j-} int_upper: {i...} rfun-ap: f(x) primrec: primrec(n;b;c) exp: i^n le: A ≤ B rgt: x > y rge: x ≥ y req_int_terms: t1 ≡ t2 rdiv: (x/y) sq_type: SQType(T) nequal: a ≠ b ∈  int_nzero: -o so_apply: x[s] so_lambda: λ2x.t[x] rev_uimplies: rev_uimplies(P;Q) uiff: uiff(P;Q) rneq: x ≠ y top: Top exists: x:A. B[x] satisfiable_int_formula: satisfiable_int_formula(fmla) not: ¬A uimplies: supposing a guard: {T} true: True less_than': less_than'(a;b) less_than: a < b false: False or: P ∨ Q decidable: Dec(P) prop: ge: i ≥  nat_plus: + squash: T sq_stable: SqStable(P) real: subtype_rel: A ⊆B sq_exists: x:A [B[x]] rless: x < y nat: rev_implies:  Q iff: ⇐⇒ Q uall: [x:A]. B[x] member: t ∈ T and: P ∧ Q implies:  Q all: x:A. B[x]
Lemmas referenced :  dyadic-scaled-rationals-dense set_wf subtype_rel_dep_function functions-equal-on-dense riiint_wf exists_wf rneq_wf member_riiint_lemma rminus_functionality rminus-int squash_wf rmul_over_rminus int_term_value_minus_lemma rsub_functionality subtract-add-cancel rmul-zero-both int_term_value_add_lemma itermAdd_wf subtype_rel_self int_formula_prop_eq_lemma intformeq_wf lelt_wf set_subtype_base decidable__equal_int int_seg_properties int_seg_wf radd_functionality rdiv_functionality rnexp2 rnexp_functionality rnexp_wf square-req-iff false_wf exp-ge-1 le_weakening2 rinv1 rfun-ap_functionality exp0_lemma req_witness ge_wf rmul-int rmul_functionality rmul-assoc req_functionality exp_step req-int nat_plus_wf rmul_preserves_req exp-positive nat_plus_subtype_nat decidable__lt fractions-req int_term_value_subtract_lemma rminus_functionality_wrt_rleq rleq_weakening_equal rleq_functionality_wrt_implies req_weakening real_term_value_const_lemma real_term_value_var_lemma real_term_value_minus_lemma real_term_value_mul_lemma real_term_value_sub_lemma real_polynomial_null rmul-rinv3 req_transitivity rmul_comm rleq_weakening rleq_functionality rmul_reverses_rleq_iff rmul-identity1 rleq_weakening_rless rmul_preserves_rleq2 rinv_wf2 req-iff-rsub-is-0 itermMinus_wf itermMultiply_wf itermSubtract_wf radd_wf subtract_wf rsub_wf rmul_wf req_wf rfun-ap_wf rless_wf all_wf rccint_wf i-member_wf nequal_wf true_wf equal_wf int_subtype_base subtype_base_sq exp_wf3 int_nzero-rational equal_functionality_wrt_subtype_rel2 int-subtype-rationals subtype_rel_set rationals_wf equal-wf-T-base not_functionality_wrt_implies rneq-int exp-positive-stronger rless-int rdiv_wf rminus_wf rmul_preserves_rleq member_rccint_lemma nat_wf int_formula_prop_wf int_formula_prop_le_lemma int_formula_prop_not_lemma int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_less_lemma int_formula_prop_and_lemma intformle_wf intformnot_wf itermVar_wf itermConstant_wf intformless_wf intformand_wf full-omega-unsat less_than_wf exp_wf_nat_plus le_wf decidable__le nat_plus_properties real_wf int-to-real_wf sq_stable__less_than nat_properties exp_wf2 rleq-int
Rules used in proof :  inlFormation hypothesis_subsumption intWeakElimination multiplyEquality minusEquality functionEquality functionExtensionality productEquality setEquality cumulativity instantiate addLevel inrFormation voidEquality voidElimination isect_memberEquality intEquality int_eqEquality dependent_pairFormation approximateComputation independent_isectElimination applyLambdaEquality equalitySymmetry equalityTransitivity independent_pairFormation because_Cache unionElimination dependent_set_memberEquality imageElimination baseClosed imageMemberEquality sqequalRule lambdaEquality applyEquality addEquality rename setElimination independent_functionElimination hypothesis hypothesisEquality isectElimination natural_numberEquality dependent_functionElimination extract_by_obid introduction cut thin productElimination sqequalHypSubstitution lambdaFormation sqequalReflexivity computationStep sqequalTransitivity sqequalSubstitution

Latex:
\mforall{}f,g:\mBbbR{}  {}\mrightarrow{}  \mBbbR{}.
    ((\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (f(x)  =  f(y))))
    {}\mRightarrow{}  (\mforall{}x,y:\mBbbR{}.    ((x  =  y)  {}\mRightarrow{}  (g(x)  =  g(y))))
    {}\mRightarrow{}  ((\mforall{}x:\mBbbR{}.  (f(-(x))  =  f(x)))
          \mwedge{}  (\mforall{}n:\mBbbZ{}.  \mforall{}y:\mBbbR{}.    (f(r(n  +  1)  *  y)  =  ((r(2)  *  f(y)  *  f(r(n)  *  y))  -  f(r(n  -  1)  *  y))))
          \mwedge{}  (\mforall{}t:\mBbbR{}.  ((f((t/r(2)))  *  f((t/r(2))))  =  (f(t)  +  r1/r(2)))))
    {}\mRightarrow{}  ((\mforall{}x:\mBbbR{}.  (g(-(x))  =  g(x)))
          \mwedge{}  (\mforall{}n:\mBbbZ{}.  \mforall{}y:\mBbbR{}.    (g(r(n  +  1)  *  y)  =  ((r(2)  *  g(y)  *  g(r(n)  *  y))  -  g(r(n  -  1)  *  y))))
          \mwedge{}  (\mforall{}t:\mBbbR{}.  ((g((t/r(2)))  *  g((t/r(2))))  =  (g(t)  +  r1/r(2)))))
    {}\mRightarrow{}  (f(r0)  =  g(r0))
    {}\mRightarrow{}  (\mforall{}a:\mBbbR{}
                ((r0  <  a)
                {}\mRightarrow{}  (f(a)  =  g(a))
                {}\mRightarrow{}  (\mforall{}x:\{x:\mBbbR{}|  x  \mmember{}  [-(a),  a]\}  .  (r0  <  f(x)))
                {}\mRightarrow{}  (\mforall{}x:\{x:\mBbbR{}|  x  \mmember{}  [-(a),  a]\}  .  (r0  <  g(x)))
                {}\mRightarrow{}  (\mforall{}x:\mBbbR{}.  (f(x)  =  g(x))))))



Date html generated: 2018_05_22-PM-03_09_01
Last ObjectModification: 2018_05_20-PM-11_41_59

Theory : reals_2


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