Nuprl Lemma : rnonzero-iff

x:ℝ(rnonzero(x) ⇐⇒ x ≠ r0)


Proof




Definitions occuring in Statement :  rneq: x ≠ y rnonzero: rnonzero(x) int-to-real: r(n) real: all: x:A. B[x] iff: ⇐⇒ Q natural_number: $n
Definitions unfolded in proof :  int-to-real: r(n) rneq: x ≠ y rnonzero: rnonzero(x) rless: x < y all: x:A. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q exists: x:A. B[x] member: t ∈ T prop: uall: [x:A]. B[x] so_lambda: λ2x.t[x] real: subtype_rel: A ⊆B nat: so_apply: x[s] rev_implies:  Q or: P ∨ Q sq_exists: x:{A| B[x]} bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) uimplies: supposing a less_than: a < b less_than': less_than'(a;b) top: Top true: True squash: T not: ¬A false: False nat_plus: + satisfiable_int_formula: satisfiable_int_formula(fmla) bfalse: ff sq_type: SQType(T) guard: {T} bnot: ¬bb ifthenelse: if then else fi  assert: b decidable: Dec(P)
Lemmas referenced :  exists_wf nat_plus_wf less_than_wf absval_wf nat_wf absval_unfold lt_int_wf bool_wf eqtt_to_assert assert_of_lt_int top_wf nat_plus_properties satisfiable-full-omega-tt intformand_wf intformless_wf itermConstant_wf itermVar_wf itermAdd_wf itermMultiply_wf int_formula_prop_and_lemma int_formula_prop_less_lemma int_term_value_constant_lemma int_term_value_var_lemma int_term_value_add_lemma int_term_value_mul_lemma int_formula_prop_wf eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot decidable__lt add-is-int-iff intformnot_wf itermMinus_wf int_formula_prop_not_lemma int_term_value_minus_lemma false_wf or_wf sq_exists_wf real_wf absval_ifthenelse assert_wf bnot_wf not_wf bool_cases iff_transitivity iff_weakening_uiff assert_of_bnot minus-is-int-iff
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity sqequalRule lambdaFormation independent_pairFormation sqequalHypSubstitution productElimination thin cut introduction extract_by_obid isectElimination hypothesis lambdaEquality natural_numberEquality applyEquality setElimination rename hypothesisEquality unionElimination dependent_pairFormation because_Cache minusEquality equalityElimination independent_isectElimination lessCases isect_memberFormation sqequalAxiom isect_memberEquality voidElimination voidEquality imageMemberEquality baseClosed imageElimination independent_functionElimination int_eqEquality intEquality dependent_functionElimination computeAll equalityTransitivity equalitySymmetry promote_hyp instantiate cumulativity dependent_set_memberEquality pointwiseFunctionality baseApply closedConclusion addEquality multiplyEquality impliesFunctionality inrFormation dependent_set_memberFormation inlFormation

Latex:
\mforall{}x:\mBbbR{}.  (rnonzero(x)  \mLeftarrow{}{}\mRightarrow{}  x  \mneq{}  r0)



Date html generated: 2017_10_03-AM-08_27_04
Last ObjectModification: 2017_07_28-AM-07_24_40

Theory : reals


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