Nuprl Lemma : real-fun-iff-continuous

a,b:ℝ.  ∀f:[a, b] ⟶ℝ(real-fun(f;a;b) ⇐⇒ real-cont(f;a;b)) supposing a ≤ b


Proof




Definitions occuring in Statement :  real-cont: real-cont(f;a;b) real-fun: real-fun(f;a;b) rfun: I ⟶ℝ rccint: [l, u] rleq: x ≤ y real: uimplies: supposing a all: x:A. B[x] iff: ⇐⇒ Q
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T uimplies: supposing a rleq: x ≤ y rnonneg: rnonneg(x) uall: [x:A]. B[x] le: A ≤ B and: P ∧ Q iff: ⇐⇒ Q implies:  Q prop: rev_implies:  Q real-fun: real-fun(f;a;b) so_lambda: λ2x.t[x] rfun: I ⟶ℝ subtype_rel: A ⊆B so_apply: x[s] continuous: f[x] continuous for x ∈ I i-approx: i-approx(I;n) rccint: [l, u] real-cont: real-cont(f;a;b) exists: x:A. B[x] sq_exists: x:A [B[x]] cand: c∧ B sq_stable: SqStable(P) squash: T rev_uimplies: rev_uimplies(P;Q) nat_plus: + rneq: x ≠ y guard: {T} or: P ∨ Q rless: x < y decidable: Dec(P) not: ¬A satisfiable_int_formula: satisfiable_int_formula(fmla) false: False top: Top rge: x ≥ y uiff: uiff(P;Q) req_int_terms: t1 ≡ t2
Lemmas referenced :  real-continuity le_witness_for_triv real-fun_wf continuous-rneq rccint_wf subtype_rel_self rfun_wf req_wf i-member_wf real-cont_wf rleq_wf real_wf nat_plus_wf icompact_wf i-approx_wf sq_stable__rless int-to-real_wf rleq_functionality_wrt_implies rabs_wf rsub_wf rdiv_wf rless-int nat_plus_properties decidable__lt full-omega-unsat intformand_wf intformnot_wf intformless_wf itermConstant_wf itermVar_wf istype-int int_formula_prop_and_lemma istype-void int_formula_prop_not_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_wf rless_wf rleq_weakening_equal rleq_weakening 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 req-iff-not-rneq rneq_wf
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation_alt hypothesis sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality isect_memberFormation_alt sqequalRule lambdaEquality_alt isectElimination productElimination equalityTransitivity equalitySymmetry independent_isectElimination functionIsTypeImplies inhabitedIsType rename independent_pairFormation universeIsType applyEquality independent_functionElimination setElimination setIsType dependent_set_memberFormation_alt natural_numberEquality imageMemberEquality baseClosed imageElimination dependent_set_memberEquality_alt because_Cache closedConclusion inrFormation_alt unionElimination approximateComputation dependent_pairFormation_alt int_eqEquality isect_memberEquality_alt voidElimination productIsType functionIsType

Latex:
\mforall{}a,b:\mBbbR{}.    \mforall{}f:[a,  b]  {}\mrightarrow{}\mBbbR{}.  (real-fun(f;a;b)  \mLeftarrow{}{}\mRightarrow{}  real-cont(f;a;b))  supposing  a  \mleq{}  b



Date html generated: 2019_10_30-AM-07_15_21
Last ObjectModification: 2019_10_09-PM-05_37_58

Theory : reals


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