Nuprl Lemma : rat-cube-dimension-one
∀k:ℕ. ∀c:ℚCube(k).
  (dim(c) = 1 ∈ ℤ ⇐⇒ ∃i:ℕk. (fst((c i)) < snd((c i)) ∧ (∀j:ℕk. ((¬(j = i ∈ ℤ)) ⇒ ((fst((c j))) = (snd((c j))) ∈ ℚ)))))
Proof
Definitions occuring in Statement : 
rat-cube-dimension: dim(c), 
rational-cube: ℚCube(k), 
qless: r < s, 
rationals: ℚ, 
int_seg: {i..j-}, 
nat: ℕ, 
pi1: fst(t), 
pi2: snd(t), 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
iff: P ⇐⇒ Q, 
not: ¬A, 
implies: P ⇒ Q, 
and: P ∧ Q, 
apply: f a, 
natural_number: $n, 
int: ℤ, 
equal: s = t ∈ T
Definitions unfolded in proof : 
decidable: Dec(P), 
inhabited-rat-interval: Inhabited(I), 
true: True, 
assert: ↑b, 
bnot: ¬bb, 
sq_type: SQType(T), 
or: P ∨ Q, 
bfalse: ff, 
ifthenelse: if b then t else f fi , 
guard: {T}, 
btrue: tt, 
it: ⋅, 
unit: Unit, 
bool: 𝔹, 
rat-interval-dimension: dim(I), 
cand: A c∧ B, 
uiff: uiff(P;Q), 
prop: ℙ, 
pi2: snd(t), 
pi1: fst(t), 
rational-interval: ℚInterval, 
rev_implies: P ⇐ Q, 
false: False, 
squash: ↓T, 
less_than: a < b, 
le: A ≤ B, 
lelt: i ≤ j < k, 
not: ¬A, 
uimplies: b supposing a, 
so_apply: x[s], 
so_lambda: λ2x.t[x], 
int_seg: {i..j-}, 
subtype_rel: A ⊆r B, 
exists: ∃x:A. B[x], 
rational-cube: ℚCube(k), 
nat: ℕ, 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
implies: P ⇒ Q, 
and: P ∧ Q, 
iff: P ⇐⇒ Q, 
all: ∀x:A. B[x]
Lemmas referenced : 
qless_irreflexivity, 
qless_transitivity_2_qorder, 
qle_weakening_eq_qorder, 
qle_weakening_lt_qorder, 
decidable__equal_int, 
q_le_wf, 
assert-q_le-eq, 
qle_antisymmetry, 
qless_complement_qorder, 
qle_wf, 
assert-bnot, 
bool_subtype_base, 
bool_wf, 
subtype_base_sq, 
bool_cases_sqequal, 
eqff_to_assert, 
iff_weakening_equal, 
assert-q_less-eq, 
eqtt_to_assert, 
q_less_wf, 
rev_implies_wf, 
rat-cube-dimension-1, 
not_wf, 
rat-cube-dimension_wf, 
equal-wf-base, 
assert-inhabited-rat-cube, 
inhabited-rat-cube_wf, 
assert_wf, 
iff_weakening_uiff, 
istype-nat, 
rational-cube_wf, 
rationals_wf, 
qless_wf, 
istype-void, 
int_subtype_base, 
lelt_wf, 
set_subtype_base, 
rat-interval-dimension_wf, 
istype-int, 
inhabited-rat-interval_wf, 
istype-assert, 
int_seg_wf
Rules used in proof : 
voidElimination, 
cumulativity, 
instantiate, 
equalityElimination, 
unionElimination, 
dependent_pairFormation_alt, 
productEquality, 
addEquality, 
minusEquality, 
promote_hyp, 
functionEquality, 
independent_functionElimination, 
dependent_functionElimination, 
equalityTransitivity, 
inhabitedIsType, 
imageElimination, 
productElimination, 
equalitySymmetry, 
sqequalBase, 
baseClosed, 
independent_isectElimination, 
lambdaEquality_alt, 
intEquality, 
equalityIstype, 
hypothesisEquality, 
applyEquality, 
hypothesis, 
because_Cache, 
rename, 
setElimination, 
natural_numberEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
universeIsType, 
functionIsType, 
productIsType, 
sqequalRule, 
independent_pairFormation, 
lambdaFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
cut
Latex:
\mforall{}k:\mBbbN{}.  \mforall{}c:\mBbbQ{}Cube(k).
    (dim(c)  =  1
    \mLeftarrow{}{}\mRightarrow{}  \mexists{}i:\mBbbN{}k.  (fst((c  i))  <  snd((c  i))  \mwedge{}  (\mforall{}j:\mBbbN{}k.  ((\mneg{}(j  =  i))  {}\mRightarrow{}  ((fst((c  j)))  =  (snd((c  j))))))))
Date html generated:
2019_10_29-AM-07_52_31
Last ObjectModification:
2019_10_27-PM-10_49_27
Theory : rationals
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