Nuprl Lemma : continuous-abs-subtype

∀[I:Interval]. ∀[f:I ⟶ℝ].  (f[x] continuous for x ∈ I ⊆r |f[x]| continuous for x ∈ I)


Proof




Definitions occuring in Statement :  continuous: f[x] continuous for x ∈ I,  rfun: I ⟶ℝ,  interval: Interval,  rabs: |x|,  subtype_rel: A ⊆r B,  uall: ∀[x:A]. B[x],  so_apply: x[s]
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  subtype_rel: A ⊆r B,  so_lambda: λ2x.t[x],  label: ...$L... t,  rfun: I ⟶ℝ,  so_apply: x[s],  prop: ℙ,  continuous-abs-ext,  implies: P ⇒ Q,  all: ∀x:A. B[x],  continuous: f[x] continuous for x ∈ I,  sq_exists: ∃x:{A| B[x]},  and: P ∧ Q,  nat_plus: ℕ+,  uimplies: b supposing a,  rneq: x ≠ y,  guard: {T},  or: P ∨ Q,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  rless: x < y,  decidable: Dec(P),  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  squash: ↓T,  true: True,  sq_stable: SqStable(P),  rleq: x ≤ y,  rnonneg: rnonneg(x),  le: A ≤ B
Lemmas referenced :  continuous_wf,  i-member_wf,  real_wf,  rfun_wf,  interval_wf,  continuous-abs-ext,  isect_wf,  rabs_wf,  equal_wf,  nat_plus_wf,  set_wf,  icompact_wf,  i-approx_wf,  rless_wf,  int-to-real_wf,  less_than_wf,  rleq_wf,  rsub_wf,  i-member-approx,  rdiv_wf,  rless-int,  nat_plus_properties,  decidable__lt,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformless_wf,  itermConstant_wf,  itermVar_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,  squash_wf,  true_wf,  iff_weakening_equal,  subtype_rel_dep_function,  rmin_wf,  rmin-idempotent-eq,  sq_exists_wf,  less_than'_wf,  sq_stable__and,  sq_stable__rless,  sq_stable__all,  sq_stable__rleq
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  lambdaEquality,  rename,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  sqequalRule,  applyEquality,  setElimination,  dependent_set_memberEquality,  hypothesis,  setEquality,  axiomEquality,  isect_memberEquality,  because_Cache,  instantiate,  equalityTransitivity,  equalitySymmetry,  functionEquality,  lambdaFormation,  dependent_functionElimination,  independent_functionElimination,  isectEquality,  functionExtensionality,  productEquality,  natural_numberEquality,  independent_isectElimination,  inrFormation,  productElimination,  unionElimination,  dependent_pairFormation,  int_eqEquality,  intEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  imageElimination,  universeEquality,  imageMemberEquality,  baseClosed,  hyp_replacement,  applyLambdaEquality,  minusEquality,  independent_pairEquality

Latex:
\mforall{}[I:Interval].  \mforall{}[f:I  {}\mrightarrow{}\mBbbR{}].    (f[x]  continuous  for  x  \mmember{}  I  \msubseteq{}r  |f[x]|  continuous  for  x  \mmember{}  I)



Date html generated: 2017_10_03-AM-10_23_04
Last ObjectModification: 2017_07_28-AM-08_07_28

Theory : reals


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