Nuprl Lemma : qmin-list-bounds
∀L:ℚ List
  (0 < ||L||
  
⇒ (∀x:ℚ
        ((x ≤ qmin-list(L) 
⇐⇒ (∀y∈L.x ≤ y))
        ∧ (qmin-list(L) ≤ x 
⇐⇒ (∃y∈L. y ≤ x))
        ∧ (x < qmin-list(L) 
⇐⇒ (∀y∈L.x < y))
        ∧ (qmin-list(L) < x 
⇐⇒ (∃y∈L. y < x)))))
Proof
Definitions occuring in Statement : 
qmin-list: qmin-list(L)
, 
qle: r ≤ s
, 
qless: r < s
, 
rationals: ℚ
, 
l_exists: (∃x∈L. P[x])
, 
l_all: (∀x∈L.P[x])
, 
length: ||as||
, 
list: T List
, 
less_than: a < b
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
natural_number: $n
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
iff: P 
⇐⇒ Q
, 
qmin: qmin(x;y)
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
uiff: uiff(P;Q)
, 
uimplies: b supposing a
, 
guard: {T}
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
, 
exists: ∃x:A. B[x]
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
bnot: ¬bb
, 
assert: ↑b
, 
false: False
, 
not: ¬A
, 
cand: A c∧ B
, 
qmin-list: qmin-list(L)
Lemmas referenced : 
rationals_wf, 
istype-less_than, 
length_wf, 
list_wf, 
combine-list-rel-and, 
qmin_wf, 
qle_wf, 
q_le_wf, 
eqtt_to_assert, 
assert-q_le-eq, 
iff_weakening_equal, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
assert-bnot, 
qmin-assoc, 
assert_wf, 
bnot_wf, 
not_wf, 
istype-assert, 
istype-void, 
qle_complement_qorder, 
qless_transitivity_1_qorder, 
qle_weakening_lt_qorder, 
qle_transitivity_qorder, 
bool_cases, 
iff_transitivity, 
iff_weakening_uiff, 
assert_of_bnot, 
combine-list-rel-or, 
uiff_transitivity2, 
equal-wf-T-base, 
qless_transitivity_2_qorder, 
qless_wf, 
qless_transitivity
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
independent_pairFormation, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
hypothesisEquality, 
dependent_functionElimination, 
sqequalRule, 
lambdaEquality_alt, 
inhabitedIsType, 
independent_functionElimination, 
productElimination, 
unionElimination, 
equalityElimination, 
because_Cache, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
dependent_pairFormation_alt, 
equalityIstype, 
promote_hyp, 
instantiate, 
cumulativity, 
voidElimination, 
productIsType, 
functionIsType, 
baseClosed, 
unionIsType, 
inlFormation_alt, 
inrFormation_alt
Latex:
\mforall{}L:\mBbbQ{}  List
    (0  <  ||L||
    {}\mRightarrow{}  (\mforall{}x:\mBbbQ{}
                ((x  \mleq{}  qmin-list(L)  \mLeftarrow{}{}\mRightarrow{}  (\mforall{}y\mmember{}L.x  \mleq{}  y))
                \mwedge{}  (qmin-list(L)  \mleq{}  x  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}y\mmember{}L.  y  \mleq{}  x))
                \mwedge{}  (x  <  qmin-list(L)  \mLeftarrow{}{}\mRightarrow{}  (\mforall{}y\mmember{}L.x  <  y))
                \mwedge{}  (qmin-list(L)  <  x  \mLeftarrow{}{}\mRightarrow{}  (\mexists{}y\mmember{}L.  y  <  x)))))
Date html generated:
2020_05_20-AM-09_16_05
Last ObjectModification:
2020_01_06-PM-05_24_48
Theory : rationals
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