Nuprl Lemma : qmul_functionality_wrt_qle
∀[a,b,c,d:ℚ].  ((a * c) ≤ (b * d)) supposing ((c ≤ d) and (a ≤ b) and (0 ≤ c) and (0 ≤ a))
Proof
Definitions occuring in Statement : 
qle: r ≤ s
, 
qmul: r * s
, 
rationals: ℚ
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
squash: ↓T
, 
and: P ∧ Q
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
cand: A c∧ B
, 
uiff: uiff(P;Q)
, 
not: ¬A
, 
false: False
, 
qle: r ≤ s
, 
grp_leq: a ≤ b
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
infix_ap: x f y
, 
grp_le: ≤b
, 
pi1: fst(t)
, 
pi2: snd(t)
, 
qadd_grp: <ℚ+>
, 
q_le: q_le(r;s)
, 
callbyvalueall: callbyvalueall, 
evalall: evalall(t)
, 
bor: p ∨bq
, 
qpositive: qpositive(r)
, 
qsub: r - s
, 
qadd: r + s
, 
qmul: r * s
, 
btrue: tt
, 
lt_int: i <z j
, 
bfalse: ff
, 
qeq: qeq(r;s)
, 
eq_int: (i =z j)
Lemmas referenced : 
decidable__equal_rationals, 
qle_witness, 
qmul_wf, 
qle_wf, 
int-subtype-rationals, 
rationals_wf, 
squash_wf, 
true_wf, 
qmul_zero_qrng, 
iff_weakening_equal, 
qmul-non-neg, 
or_wf, 
equal-wf-T-base, 
qless_wf, 
qle_transitivity_qorder, 
qle-iff, 
qle_antisymmetry, 
qle_weakening_eq_qorder, 
qmul_preserves_qle2, 
qmul_comm_qrng
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
natural_numberEquality, 
hypothesis, 
applyEquality, 
because_Cache, 
sqequalRule, 
unionElimination, 
isectElimination, 
independent_functionElimination, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
lambdaEquality, 
imageElimination, 
productElimination, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
independent_isectElimination, 
hyp_replacement, 
Error :applyLambdaEquality, 
inlFormation, 
productEquality, 
minusEquality, 
inrFormation, 
independent_pairFormation, 
promote_hyp, 
equalityElimination, 
voidElimination
Latex:
\mforall{}[a,b,c,d:\mBbbQ{}].    ((a  *  c)  \mleq{}  (b  *  d))  supposing  ((c  \mleq{}  d)  and  (a  \mleq{}  b)  and  (0  \mleq{}  c)  and  (0  \mleq{}  a))
Date html generated:
2016_10_25-PM-00_07_50
Last ObjectModification:
2016_07_12-AM-07_50_49
Theory : rationals
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