Nuprl Lemma : IVT-locally-non-constant-open

a:ℝ. ∀b:{b:ℝa < b} . ∀f:[a, b] ⟶ℝ.
  (∀a',b':ℝ.  (((a < a') ∧ (a' < b') ∧ (b' < b))  (∀c:ℝlocally-non-constant(f;a';b';c))))
   (∀c:ℝ((f(a) < c)  (c < f(b))  (∃x:ℝ((x ∈ (a, b)) ∧ (f(x) c))))) 
  supposing ∀x,y:{x:ℝx ∈ [a, b]} .  ((x y)  (f[x] f[y]))


Proof




Definitions occuring in Statement :  locally-non-constant: locally-non-constant(f;a;b;c) r-ap: f(x) rfun: I ⟶ℝ rooint: (l, u) rccint: [l, u] i-member: r ∈ I rless: x < y req: y real: uimplies: supposing a so_apply: x[s] all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q set: {x:A| B[x]} 
Definitions unfolded in proof :  all: x:A. B[x] subinterval: I ⊆  member: t ∈ T top: Top implies:  Q and: P ∧ Q cand: c∧ B uall: [x:A]. B[x] guard: {T} uimplies: supposing a prop: sq_stable: SqStable(P) squash: T so_apply: x[s] rfun: I ⟶ℝ so_lambda: λ2x.t[x] i-member: r ∈ I rccint: [l, u] subtype_rel: A ⊆B continuous: f[x] continuous for x ∈ I i-approx: i-approx(I;n) nat_plus: + rless: x < y sq_exists: x:A [B[x]] decidable: Dec(P) or: P ∨ Q not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False iff: ⇐⇒ Q rneq: x ≠ y rev_implies:  Q rleq: x ≤ y rnonneg: rnonneg(x) le: A ≤ B uiff: uiff(P;Q) req_int_terms: t1 ≡ t2 rev_uimplies: rev_uimplies(P;Q) less_than': less_than'(a;b) rge: x ≥ y r-ap: f(x) rdiv: (x/y)
Lemmas referenced :  member_rooint_lemma istype-void member_rccint_lemma rleq_weakening_rless rless_wf sq_stable__rless req_witness function-is-continuous r-ap_wf rccint_wf rleq_weakening_equal locally-non-constant_wf rfun_subtype_3 i-member_wf req_wf rfun_wf real_wf nat_plus_properties decidable__lt full-omega-unsat intformnot_wf intformless_wf itermConstant_wf istype-int int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_formula_prop_wf istype-less_than rccint-icompact icompact_wf small-reciprocal-real rless-implies-rless int-to-real_wf rsub_wf sq_stable__and all_wf rleq_wf rabs_wf rdiv_wf rless-int intformand_wf itermVar_wf int_formula_prop_and_lemma int_term_value_var_lemma sq_stable__all sq_stable__rleq le_witness_for_triv itermSubtract_wf req-iff-rsub-is-0 real_polynomial_null real_term_value_sub_lemma real_term_value_var_lemma real_term_value_const_lemma ravg-between rmin_strict_ub radd_wf ravg_wf trivial-rless-radd rmin_strict_lb rmin_wf rabs-difference-bound-rleq radd-preserves-rleq rminus_wf itermAdd_wf itermMinus_wf rmin_ub rleq_functionality real_term_value_add_lemma rmin_lb real_term_value_minus_lemma rmul_wf itermMultiply_wf rmul-nonneg-case1 rleq-int istype-false real_term_value_mul_lemma rleq_functionality_wrt_implies radd_functionality_wrt_rleq req_weakening rinv_wf2 req_transitivity radd_functionality rinv-as-rdiv radd-preserves-rless rless_functionality_wrt_implies rless_functionality rmax_strict_lb trivial-rsub-rless rmax_strict_ub rmax_wf rless_transitivity2 rleq-rmax rmax_lb trivial-rleq-radd nat_plus_wf IVT-locally-non-constant rless_transitivity1 sq_stable__req sq_stable__i-member rleq_transitivity rleq_weakening req_inversion continuous-implies-functional
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt cut sqequalRule introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination thin isect_memberEquality_alt voidElimination hypothesis productElimination isectElimination hypothesisEquality independent_isectElimination independent_pairFormation setElimination rename because_Cache productIsType universeIsType independent_functionElimination imageMemberEquality baseClosed imageElimination isect_memberFormation_alt lambdaEquality_alt applyEquality functionIsTypeImplies inhabitedIsType promote_hyp functionIsType setIsType dependent_set_memberEquality_alt natural_numberEquality unionElimination approximateComputation dependent_pairFormation_alt functionEquality productEquality closedConclusion inrFormation_alt int_eqEquality equalityTransitivity equalitySymmetry inlFormation_alt

Latex:
\mforall{}a:\mBbbR{}.  \mforall{}b:\{b:\mBbbR{}|  a  <  b\}  .  \mforall{}f:[a,  b]  {}\mrightarrow{}\mBbbR{}.
    (\mforall{}a',b':\mBbbR{}.    (((a  <  a')  \mwedge{}  (a'  <  b')  \mwedge{}  (b'  <  b))  {}\mRightarrow{}  (\mforall{}c:\mBbbR{}.  locally-non-constant(f;a';b';c))))
    {}\mRightarrow{}  (\mforall{}c:\mBbbR{}.  ((f(a)  <  c)  {}\mRightarrow{}  (c  <  f(b))  {}\mRightarrow{}  (\mexists{}x:\mBbbR{}.  ((x  \mmember{}  (a,  b))  \mwedge{}  (f(x)  =  c))))) 
    supposing  \mforall{}x,y:\{x:\mBbbR{}|  x  \mmember{}  [a,  b]\}  .    ((x  =  y)  {}\mRightarrow{}  (f[x]  =  f[y]))



Date html generated: 2019_10_30-AM-09_09_15
Last ObjectModification: 2019_04_02-AM-11_58_05

Theory : reals


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