Nuprl Lemma : continuous-minus

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


Proof




Definitions occuring in Statement :  continuous: f[x] continuous for x ∈ I rfun: I ⟶ℝ interval: Interval rminus: -(x) uall: [x:A]. B[x] so_apply: x[s] implies:  Q
Definitions unfolded in proof :  uall: [x:A]. B[x] implies:  Q continuous: f[x] continuous for x ∈ I all: x:A. B[x] member: t ∈ T sq_exists: x:{A| B[x]} and: P ∧ Q cand: c∧ B prop: so_lambda: λ2x.t[x] nat_plus: + so_apply: x[s] rfun: I ⟶ℝ uimplies: supposing a rneq: x ≠ y guard: {T} or: P ∨ Q iff: ⇐⇒ Q rev_implies:  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 label: ...$L... t squash: T true: True subtype_rel: A ⊆B rsub: y uiff: uiff(P;Q) rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced :  radd_comm rminus-rminus req_transitivity req_inversion rminus-as-rmul rmul_functionality radd_functionality req_weakening rminus-radd rabs_functionality rleq_functionality uiff_transitivity rmul_wf radd_wf iff_weakening_equal rabs-rminus true_wf squash_wf interval_wf rfun_wf continuous_wf icompact_wf set_wf nat_plus_wf int_formula_prop_wf int_term_value_var_lemma int_term_value_constant_lemma int_formula_prop_less_lemma int_formula_prop_not_lemma int_formula_prop_and_lemma itermVar_wf itermConstant_wf intformless_wf intformnot_wf intformand_wf satisfiable-full-omega-tt decidable__lt nat_plus_properties rless-int rdiv_wf i-member-approx rminus_wf less_than_wf all_wf int-to-real_wf rless_wf real_wf i-approx_wf i-member_wf rsub_wf rabs_wf rleq_wf
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation lambdaFormation sqequalHypSubstitution cut hypothesis dependent_functionElimination thin hypothesisEquality setElimination rename dependent_set_memberFormation productElimination independent_pairFormation because_Cache independent_functionElimination lemma_by_obid isectElimination productEquality natural_numberEquality sqequalRule lambdaEquality functionEquality dependent_set_memberEquality applyEquality independent_isectElimination inrFormation unionElimination dependent_pairFormation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality computeAll setEquality imageElimination equalityTransitivity equalitySymmetry imageMemberEquality baseClosed universeEquality minusEquality

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



Date html generated: 2016_05_18-AM-09_11_38
Last ObjectModification: 2016_01_17-AM-02_38_34

Theory : reals


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