Nuprl Lemma : rpositive-iff

[x:ℝ]. (rpositive(x) ⇐⇒ rpositive2(x))


Proof




Definitions occuring in Statement :  rpositive2: rpositive2(x) rpositive: rpositive(x) real: uall: [x:A]. B[x] iff: ⇐⇒ Q
Definitions unfolded in proof :  rpositive2: rpositive2(x) uall: [x:A]. B[x] iff: ⇐⇒ Q and: P ∧ Q implies:  Q member: t ∈ T prop: real: rev_implies:  Q exists: x:A. B[x] so_lambda: λ2x.t[x] nat_plus: + so_apply: x[s] rpositive: rpositive(x) sq_exists: x:{A| B[x]} all: x:A. B[x] uimplies: supposing a bool: 𝔹 unit: Unit it: btrue: tt uiff: uiff(P;Q) ifthenelse: if then else fi  le: A ≤ B decidable: Dec(P) or: P ∨ Q less_than: a < b squash: T satisfiable_int_formula: satisfiable_int_formula(fmla) false: False not: ¬A top: Top bfalse: ff sq_type: SQType(T) guard: {T} bnot: ¬bb assert: b regular-int-seq: k-regular-seq(f) subtype_rel: A ⊆B nat: true: True less_than': less_than'(a;b)
Lemmas referenced :  rpositive_wf exists_wf nat_plus_wf all_wf le_wf real_wf rnonzero-lemma1 absval_ifthenelse lt_int_wf bool_wf eqtt_to_assert assert_of_lt_int nat_plus_properties decidable__le less_than_wf satisfiable-full-omega-tt intformand_wf intformnot_wf intformle_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_not_lemma int_formula_prop_le_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf eqff_to_assert equal_wf bool_cases_sqequal subtype_base_sq bool_subtype_base assert-bnot less_than'_wf assert_wf bnot_wf not_wf bool_cases iff_transitivity iff_weakening_uiff assert_of_bnot mul_preserves_le nat_plus_subtype_nat multiply-is-int-iff int_subtype_base minus-is-int-iff false_wf mul_preserves_lt squash_wf true_wf absval_pos subtract_wf decidable__lt itermSubtract_wf itermMultiply_wf int_term_value_subtract_lemma int_term_value_mul_lemma mul_nat_plus itermAdd_wf int_term_value_add_lemma iff_weakening_equal mul_cancel_in_lt
Rules used in proof :  sqequalSubstitution sqequalRule sqequalReflexivity sqequalTransitivity computationStep isect_memberFormation independent_pairFormation lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution isectElimination thin setElimination rename hypothesisEquality hypothesis productElimination lambdaEquality functionEquality because_Cache multiplyEquality applyEquality dependent_pairFormation independent_isectElimination natural_numberEquality unionElimination equalityElimination equalityTransitivity equalitySymmetry dependent_functionElimination dependent_set_memberEquality imageElimination int_eqEquality intEquality isect_memberEquality voidElimination voidEquality computeAll promote_hyp instantiate cumulativity independent_functionElimination independent_pairEquality axiomEquality impliesFunctionality functionExtensionality baseClosed baseApply closedConclusion pointwiseFunctionality addEquality imageMemberEquality universeEquality dependent_set_memberFormation

Latex:
\mforall{}[x:\mBbbR{}].  (rpositive(x)  \mLeftarrow{}{}\mRightarrow{}  rpositive2(x))



Date html generated: 2017_10_03-AM-08_23_14
Last ObjectModification: 2017_07_28-AM-07_22_46

Theory : reals


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