Nuprl Lemma : rmul_reverses_rless_iff
∀x,y,z:ℝ.  ((y < r0) 
⇒ (x < z 
⇐⇒ (z * y) < (x * y)))
Proof
Definitions occuring in Statement : 
rless: x < y
, 
rmul: a * b
, 
int-to-real: r(n)
, 
real: ℝ
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
rev_implies: P 
⇐ Q
, 
uimplies: b supposing a
, 
rneq: x ≠ y
, 
or: P ∨ Q
, 
rdiv: (x/y)
, 
itermConstant: "const"
, 
req_int_terms: t1 ≡ t2
, 
false: False
, 
not: ¬A
, 
top: Top
, 
uiff: uiff(P;Q)
, 
rev_uimplies: rev_uimplies(P;Q)
Lemmas referenced : 
rless_wf, 
rmul_wf, 
int-to-real_wf, 
real_wf, 
rmul_reverses_rless, 
rdiv_wf, 
rinv-negative, 
rless-implies-rless, 
rinv_wf2, 
real_term_polynomial, 
itermSubtract_wf, 
itermConstant_wf, 
itermVar_wf, 
itermMultiply_wf, 
real_term_value_const_lemma, 
real_term_value_sub_lemma, 
real_term_value_var_lemma, 
real_term_value_mul_lemma, 
req-iff-rsub-is-0, 
rsub_wf, 
req_wf, 
req_weakening, 
rless_functionality, 
uiff_transitivity, 
req_functionality, 
req_inversion, 
rmul-assoc, 
rmul_functionality, 
rmul_comm, 
req_transitivity, 
rmul-ac, 
rmul-rdiv-cancel, 
rmul-one-both
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
independent_pairFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
natural_numberEquality, 
independent_functionElimination, 
dependent_functionElimination, 
lemma_by_obid, 
independent_isectElimination, 
inlFormation, 
because_Cache, 
sqequalRule, 
computeAll, 
lambdaEquality, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
productElimination, 
promote_hyp
Latex:
\mforall{}x,y,z:\mBbbR{}.    ((y  <  r0)  {}\mRightarrow{}  (x  <  z  \mLeftarrow{}{}\mRightarrow{}  (z  *  y)  <  (x  *  y)))
Date html generated:
2017_10_03-AM-08_35_08
Last ObjectModification:
2017_07_28-AM-07_28_50
Theory : reals
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