Nuprl Lemma : rabs-rmul

[x,y:ℝ].  (|x y| (|x| |y|))


Proof




Definitions occuring in Statement :  rabs: |x| req: y rmul: b real: uall: [x:A]. B[x]
Definitions unfolded in proof :  uall: [x:A]. B[x] member: t ∈ T uiff: uiff(P;Q) and: P ∧ Q uimplies: supposing a all: x:A. B[x] subtype_rel: A ⊆B real: reg-seq-mul: reg-seq-mul(x;y) rabs: |x| nat_plus: + nequal: a ≠ b ∈  not: ¬A implies:  Q satisfiable_int_formula: satisfiable_int_formula(fmla) exists: x:A. B[x] false: False top: Top prop: iff: ⇐⇒ Q rev_implies:  Q bdd-diff: bdd-diff(f;g) nat: le: A ≤ B less_than': less_than'(a;b) so_lambda: λ2x.t[x] ge: i ≥  so_apply: x[s] true: True squash: T guard: {T} less_than: a < b absval: |i| subtract: m
Lemmas referenced :  req-iff-bdd-diff rabs_wf rmul_wf bdd-diff_functionality absval_wf nat_plus_properties satisfiable-full-omega-tt intformand_wf intformeq_wf itermMultiply_wf itermConstant_wf itermVar_wf intformless_wf int_formula_prop_and_lemma int_formula_prop_eq_lemma int_term_value_mul_lemma int_term_value_constant_lemma int_term_value_var_lemma int_formula_prop_less_lemma int_formula_prop_wf equal-wf-base int_subtype_base nat_plus_wf reg-seq-mul_wf rabs_functionality_wrt_bdd-diff rmul-bdd-diff-reg-seq-mul false_wf le_wf all_wf subtract_wf nat_properties req_witness real_wf nat_wf squash_wf true_wf absval_mul iff_weakening_equal equal_wf absval_div_nat mul_nat_plus less_than_wf minus-one-mul add-mul-special zero-mul
Rules used in proof :  sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity isect_memberFormation introduction cut extract_by_obid sqequalHypSubstitution isectElimination thin hypothesisEquality hypothesis productElimination independent_isectElimination dependent_functionElimination applyEquality lambdaEquality setElimination rename because_Cache sqequalRule divideEquality multiplyEquality natural_numberEquality lambdaFormation dependent_pairFormation int_eqEquality intEquality isect_memberEquality voidElimination voidEquality independent_pairFormation computeAll baseApply closedConclusion baseClosed independent_functionElimination dependent_set_memberEquality imageElimination equalityTransitivity equalitySymmetry imageMemberEquality universeEquality functionExtensionality

Latex:
\mforall{}[x,y:\mBbbR{}].    (|x  *  y|  =  (|x|  *  |y|))



Date html generated: 2017_10_03-AM-08_23_07
Last ObjectModification: 2017_07_28-AM-07_22_43

Theory : reals


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