Nuprl Lemma : iroot-positive
∀[n,x:ℕ+].  (1 ≤ iroot(n;x))
Proof
Definitions occuring in Statement : 
iroot: iroot(n;x), 
nat_plus: ℕ+, 
uall: ∀[x:A]. B[x], 
le: A ≤ B, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
subtype_rel: A ⊆r B, 
all: ∀x:A. B[x], 
decidable: Dec(P), 
or: P ∨ Q, 
and: P ∧ Q, 
le: A ≤ B, 
not: ¬A, 
implies: P ⇒ Q, 
false: False, 
prop: ℙ, 
nat: ℕ, 
guard: {T}, 
nat_plus: ℕ+, 
ge: i ≥ j , 
uimplies: b supposing a, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
top: Top, 
sq_type: SQType(T), 
squash: ↓T, 
true: True, 
iff: P ⇐⇒ Q
Lemmas referenced : 
int_formula_prop_less_lemma, 
intformless_wf, 
iff_weakening_equal, 
exp-one, 
true_wf, 
squash_wf, 
less_than_wf, 
int_subtype_base, 
subtype_base_sq, 
int_formula_prop_wf, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_formula_prop_eq_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_and_lemma, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
intformeq_wf, 
intformnot_wf, 
intformand_wf, 
satisfiable-full-omega-tt, 
decidable__equal_int, 
nat_plus_properties, 
le_wf, 
nat_properties, 
nat_plus_subtype_nat, 
nat_plus_wf, 
less_than'_wf, 
iroot_wf, 
decidable__le, 
iroot-property
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
applyEquality, 
because_Cache, 
hypothesis, 
sqequalRule, 
dependent_functionElimination, 
natural_numberEquality, 
unionElimination, 
productElimination, 
independent_pairEquality, 
lambdaEquality, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
voidElimination, 
setElimination, 
rename, 
setEquality, 
intEquality, 
independent_isectElimination, 
dependent_pairFormation, 
int_eqEquality, 
voidEquality, 
independent_pairFormation, 
computeAll, 
instantiate, 
cumulativity, 
independent_functionElimination, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
universeEquality
Latex:
\mforall{}[n,x:\mBbbN{}\msupplus{}].    (1  \mleq{}  iroot(n;x))
Date html generated:
2019_06_20-PM-02_34_51
Last ObjectModification:
2019_03_19-AM-10_49_36
Theory : num_thy_1
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