Nuprl Lemma : rabs-rmul
∀[x,y:ℝ].  (|x * y| = (|x| * |y|))
Proof
Definitions occuring in Statement : 
rabs: |x|
, 
req: x = y
, 
rmul: a * b
, 
real: ℝ
, 
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: b supposing a
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
real: ℝ
, 
reg-seq-mul: reg-seq-mul(x;y)
, 
rabs: |x|
, 
nat_plus: ℕ+
, 
nequal: a ≠ b ∈ T 
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
top: Top
, 
prop: ℙ
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
bdd-diff: bdd-diff(f;g)
, 
nat: ℕ
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
so_lambda: λ2x.t[x]
, 
ge: i ≥ j 
, 
so_apply: x[s]
, 
true: True
, 
squash: ↓T
, 
guard: {T}
, 
less_than: a < b
, 
absval: |i|
, 
subtract: n - 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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