Nuprl Lemma : square-rleq-implies
∀x,y:ℝ.  ((r0 ≤ y) ⇒ (x^2 ≤ y^2) ⇒ (x ≤ y))
Proof
Definitions occuring in Statement : 
rleq: x ≤ y, 
rnexp: x^k1, 
int-to-real: r(n), 
real: ℝ, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
nat_plus: ℕ+, 
less_than: a < b, 
squash: ↓T, 
less_than': less_than'(a;b), 
true: True, 
and: P ∧ Q, 
prop: ℙ, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q, 
nat: ℕ, 
le: A ≤ B, 
false: False, 
not: ¬A, 
uimplies: b supposing a, 
uiff: uiff(P;Q), 
rev_uimplies: rev_uimplies(P;Q), 
top: Top, 
guard: {T}
Lemmas referenced : 
rnexp-rleq-iff, 
rabs_wf, 
zero-rleq-rabs, 
less_than_wf, 
rleq_wf, 
rnexp_wf, 
false_wf, 
le_wf, 
int-to-real_wf, 
real_wf, 
rnexp2-nonneg, 
rleq_functionality, 
req_inversion, 
rabs-rnexp, 
req_weakening, 
rabs-of-nonneg, 
rabs-as-rmax, 
rleq-rmax, 
rminus_wf, 
rleq_transitivity
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isectElimination, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
dependent_set_memberEquality, 
natural_numberEquality, 
sqequalRule, 
independent_pairFormation, 
imageMemberEquality, 
baseClosed, 
productElimination, 
because_Cache, 
independent_isectElimination, 
isect_memberEquality, 
voidElimination, 
voidEquality
Latex:
\mforall{}x,y:\mBbbR{}.    ((r0  \mleq{}  y)  {}\mRightarrow{}  (x\^{}2  \mleq{}  y\^{}2)  {}\mRightarrow{}  (x  \mleq{}  y))
Date html generated:
2016_10_26-AM-09_08_50
Last ObjectModification:
2016_09_30-AM-10_54_12
Theory : reals
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