Nuprl Lemma : rpositive-radd

x,y:ℝ.  (rpositive(x)  rpositive(y)  rpositive(x y))


Proof




Definitions occuring in Statement :  rpositive: rpositive(x) radd: b real: all: x:A. B[x] implies:  Q
Definitions unfolded in proof :  all: x:A. B[x] implies:  Q radd: b member: t ∈ T uall: [x:A]. B[x] nat_plus: + less_than: a < b squash: T less_than': less_than'(a;b) true: True and: P ∧ Q prop: subtype_rel: A ⊆B top: Top real: iff: ⇐⇒ Q rev_implies:  Q uimplies: supposing a guard: {T} rpositive2: rpositive2(x) exists: x:A. B[x] decidable: Dec(P) or: P ∨ Q satisfiable_int_formula: satisfiable_int_formula(fmla) false: False not: ¬A so_lambda: λ2x.t[x] so_apply: x[s] uiff: uiff(P;Q) nat: le: A ≤ B
Lemmas referenced :  rpositive2_functionality accelerate_wf less_than_wf reg-seq-list-add_wf cons_wf real_wf nil_wf length_of_cons_lemma length_of_nil_lemma nat_plus_wf regular-int-seq_wf length_wf accelerate-bdd-diff rpositive2_wf squash_wf true_wf reg-seq-list-add-as-l_sum iff_weakening_equal map_cons_lemma map_nil_lemma l_sum_cons_lemma l_sum_nil_lemma rpositive-iff radd_wf rpositive_wf imax_wf imax_nat_plus nat_plus_properties decidable__lt satisfiable-full-omega-tt intformand_wf intformnot_wf intformless_wf itermConstant_wf itermVar_wf intformeq_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_eq_lemma int_formula_prop_wf equal_wf le_wf all_wf imax_lb right_mul_preserves_le imax_ub decidable__le intformle_wf int_formula_prop_le_lemma mul_preserves_lt multiply-is-int-iff false_wf itermMultiply_wf int_term_value_mul_lemma itermAdd_wf int_term_value_add_lemma
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation cut introduction extract_by_obid sqequalHypSubstitution dependent_functionElimination thin isectElimination dependent_set_memberEquality natural_numberEquality sqequalRule independent_pairFormation imageMemberEquality hypothesisEquality baseClosed hypothesis applyEquality lambdaEquality isect_memberEquality voidElimination voidEquality setEquality functionEquality intEquality functionExtensionality setElimination rename because_Cache independent_functionElimination productElimination imageElimination equalityTransitivity equalitySymmetry universeEquality independent_isectElimination addLevel impliesFunctionality dependent_pairFormation applyLambdaEquality unionElimination int_eqEquality computeAll multiplyEquality addEquality inrFormation pointwiseFunctionality promote_hyp baseApply closedConclusion inlFormation

Latex:
\mforall{}x,y:\mBbbR{}.    (rpositive(x)  {}\mRightarrow{}  rpositive(y)  {}\mRightarrow{}  rpositive(x  +  y))



Date html generated: 2017_10_03-AM-08_23_20
Last ObjectModification: 2017_07_28-AM-07_22_49

Theory : reals


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