Nuprl Lemma : general-iroot-property
∀[n:ℕ+]. ∀[x:ℤ].
  (((0 ≤ x) ⇒ ((general-iroot(n;x)^n ≤ x) ∧ x < (general-iroot(n;x) + 1)^n))
  ∧ ((x < 0 ∧ ((n mod 2) = 1 ∈ ℤ)) ⇒ ((x ≤ general-iroot(n;x)^n) ∧ (general-iroot(n;x) - 1)^n < x))
  ∧ ((x < 0 ∧ ((n mod 2) = 0 ∈ ℤ)) ⇒ (general-iroot(n;x) = 0 ∈ ℤ)))
Proof
Definitions occuring in Statement : 
general-iroot: general-iroot(n;x), 
exp: i^n, 
modulus: a mod n, 
nat_plus: ℕ+, 
less_than: a < b, 
uall: ∀[x:A]. B[x], 
le: A ≤ B, 
implies: P ⇒ Q, 
and: P ∧ Q, 
subtract: n - m, 
add: n + m, 
natural_number: $n, 
int: ℤ, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
and: P ∧ Q, 
implies: P ⇒ Q, 
general-iroot: general-iroot(n;x), 
prop: ℙ, 
subtype_rel: A ⊆r B, 
nat_plus: ℕ+, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
uimplies: b supposing a, 
has-value: (a)↓, 
all: ∀x:A. B[x], 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
less_than: a < b, 
less_than': less_than'(a;b), 
top: Top, 
true: True, 
squash: ↓T, 
not: ¬A, 
false: False, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
bfalse: ff, 
or: P ∨ Q, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
nequal: a ≠ b ∈ T , 
le: A ≤ B, 
cand: A c∧ B, 
nat: ℕ, 
int_lower: {...i}, 
sq_exists: ∃x:A [B[x]], 
decidable: Dec(P), 
sq_stable: SqStable(P)
Lemmas referenced : 
le_wf, 
less_than_wf, 
equal-wf-T-base, 
modulus_wf_int_mod, 
subtype_rel_set, 
int_mod_wf, 
int-subtype-int_mod, 
value-type-has-value, 
nat_plus_wf, 
set-value-type, 
int-value-type, 
lt_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
top_wf, 
eq_int_wf, 
assert_of_eq_int, 
nat_plus_properties, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformeq_wf, 
itermVar_wf, 
itermConstant_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_eq_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
neg_assert_of_eq_int, 
member-less_than, 
less_than'_wf, 
exp_wf2, 
nat_plus_subtype_nat, 
general-iroot_wf, 
subtract_wf, 
intformless_wf, 
intformle_wf, 
int_formula_prop_less_lemma, 
int_formula_prop_le_lemma, 
iroot-property, 
int_subtype_base, 
integer-nth-root2, 
all_wf, 
int_lower_wf, 
sq_exists_wf, 
decidable__le, 
intformnot_wf, 
int_formula_prop_not_lemma, 
squash_wf, 
sq_stable__and, 
sq_stable__le, 
sq_stable__less_than
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
lambdaFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
natural_numberEquality, 
hypothesisEquality, 
hypothesis, 
productEquality, 
because_Cache, 
applyEquality, 
sqequalRule, 
intEquality, 
lambdaEquality, 
independent_isectElimination, 
baseClosed, 
callbyvalueReduce, 
productElimination, 
unionElimination, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
lessCases, 
sqequalAxiom, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
imageMemberEquality, 
imageElimination, 
independent_functionElimination, 
dependent_set_memberEquality, 
int_eqReduceTrueSq, 
setElimination, 
rename, 
dependent_pairFormation, 
int_eqEquality, 
dependent_functionElimination, 
computeAll, 
promote_hyp, 
instantiate, 
cumulativity, 
int_eqReduceFalseSq, 
independent_pairEquality, 
axiomEquality, 
addEquality, 
setEquality
Latex:
\mforall{}[n:\mBbbN{}\msupplus{}].  \mforall{}[x:\mBbbZ{}].
    (((0  \mleq{}  x)  {}\mRightarrow{}  ((general-iroot(n;x)\^{}n  \mleq{}  x)  \mwedge{}  x  <  (general-iroot(n;x)  +  1)\^{}n))
    \mwedge{}  ((x  <  0  \mwedge{}  ((n  mod  2)  =  1))  {}\mRightarrow{}  ((x  \mleq{}  general-iroot(n;x)\^{}n)  \mwedge{}  (general-iroot(n;x)  -  1)\^{}n  <  x))
    \mwedge{}  ((x  <  0  \mwedge{}  ((n  mod  2)  =  0))  {}\mRightarrow{}  (general-iroot(n;x)  =  0)))
Date html generated:
2018_05_21-PM-07_50_59
Last ObjectModification:
2017_07_26-PM-05_28_46
Theory : general
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