Nuprl Lemma : rmul_preserves_rleq3
∀[x,y,a,b:ℝ].  ((x * y) ≤ (a * b)) supposing ((x ≤ a) and (y ≤ b) and ((r0 ≤ x) ∧ (r0 ≤ y)))
Proof
Definitions occuring in Statement : 
rleq: x ≤ y, 
rmul: a * b, 
int-to-real: r(n), 
real: ℝ, 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
and: P ∧ Q, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
uimplies: b supposing a, 
and: P ∧ Q, 
guard: {T}, 
rleq: x ≤ y, 
rnonneg: rnonneg(x), 
all: ∀x:A. B[x], 
le: A ≤ B, 
prop: ℙ, 
uiff: uiff(P;Q), 
req_int_terms: t1 ≡ t2, 
false: False, 
implies: P ⇒ Q, 
not: ¬A, 
top: Top, 
rev_uimplies: rev_uimplies(P;Q), 
rge: x ≥ y
Lemmas referenced : 
rmul_preserves_rleq2, 
rleq_transitivity, 
int-to-real_wf, 
le_witness_for_triv, 
rleq_wf, 
real_wf, 
rmul_wf, 
itermSubtract_wf, 
itermMultiply_wf, 
itermVar_wf, 
rleq_functionality, 
req-iff-rsub-is-0, 
real_polynomial_null, 
istype-int, 
real_term_value_sub_lemma, 
istype-void, 
real_term_value_mul_lemma, 
real_term_value_var_lemma, 
real_term_value_const_lemma, 
rleq_functionality_wrt_implies, 
rleq_weakening_equal
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
introduction, 
cut, 
sqequalHypSubstitution, 
productElimination, 
thin, 
extract_by_obid, 
isectElimination, 
hypothesisEquality, 
independent_isectElimination, 
hypothesis, 
natural_numberEquality, 
promote_hyp, 
sqequalRule, 
lambdaEquality_alt, 
dependent_functionElimination, 
equalityTransitivity, 
equalitySymmetry, 
functionIsTypeImplies, 
inhabitedIsType, 
universeIsType, 
isect_memberEquality_alt, 
isectIsTypeImplies, 
productIsType, 
because_Cache, 
approximateComputation, 
int_eqEquality, 
voidElimination
Latex:
\mforall{}[x,y,a,b:\mBbbR{}].    ((x  *  y)  \mleq{}  (a  *  b))  supposing  ((x  \mleq{}  a)  and  (y  \mleq{}  b)  and  ((r0  \mleq{}  x)  \mwedge{}  (r0  \mleq{}  y)))
Date html generated:
2019_10_29-AM-09_38_11
Last ObjectModification:
2019_02_04-AM-10_02_05
Theory : reals
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