Nuprl Lemma : qdiv_functionality_wrt_qless2
∀[a,b,c,d:ℚ].  ((a/c) < (b/d)) supposing (d < c and (a ≤ b) and 0 < d and 0 < a)
Proof
Definitions occuring in Statement : 
qle: r ≤ s
, 
qless: r < s
, 
qdiv: (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
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
false: False
, 
prop: ℙ
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
rev_uimplies: rev_uimplies(P;Q)
, 
squash: ↓T
, 
true: True
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
qless_transitivity_1_qorder, 
qle_witness, 
qle_weakening_lt_qorder, 
qmul_preserves_qle2, 
qmul_ac_1_qrng, 
qmul_comm_qrng, 
iff_weakening_equal, 
qmul_wf, 
int-subtype-rationals, 
qmul-qdiv-cancel, 
true_wf, 
squash_wf, 
qmul_preserves_qless, 
qle_wf, 
qless_wf, 
rationals_wf, 
equal_wf, 
qless_irreflexivity, 
qle_weakening_eq_qorder, 
qless_transitivity_2_qorder, 
qless_transitivity, 
qdiv_wf, 
qless_witness
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
because_Cache, 
independent_isectElimination, 
lambdaFormation, 
hypothesis, 
natural_numberEquality, 
applyEquality, 
sqequalRule, 
hypothesisEquality, 
voidElimination, 
independent_functionElimination, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
lambdaEquality, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
independent_pairFormation
Latex:
\mforall{}[a,b,c,d:\mBbbQ{}].    ((a/c)  <  (b/d))  supposing  (d  <  c  and  (a  \mleq{}  b)  and  0  <  d  and  0  <  a)
Date html generated:
2016_05_15-PM-11_04_40
Last ObjectModification:
2016_01_16-PM-09_28_26
Theory : rationals
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