Nuprl Lemma : tsqrt-unique

∀[n,x:ℕ].  (((t(x) ≤ n) ∧ n < t(x + 1)) ⇒ (x = tsqrt(n) ∈ ℤ))


Proof




Definitions occuring in Statement :  tsqrt: tsqrt(n),  triangular-num: t(n),  nat: ℕ,  less_than: a < b,  uall: ∀[x:A]. B[x],  le: A ≤ B,  implies: P ⇒ Q,  and: P ∧ Q,  add: n + m,  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  member: t ∈ T,  implies: P ⇒ Q,  and: P ∧ Q,  prop: ℙ,  subtype_rel: A ⊆r B,  nat: ℕ,  ge: i ≥ j ,  all: ∀x:A. B[x],  decidable: Dec(P),  or: P ∨ Q,  uimplies: b supposing a,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  top: Top,  less_than: a < b,  squash: ↓T,  le: A ≤ B,  less_than': less_than'(a;b),  guard: {T}
Lemmas referenced :  tsqrt-property,  le_wf,  triangular-num_wf,  less_than_wf,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermAdd_wf,  itermVar_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_le_lemma,  int_term_value_constant_lemma,  int_term_value_add_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  nat_wf,  decidable__lt,  tsqrt_wf,  triangular-num-le,  intformless_wf,  int_formula_prop_less_lemma,  decidable__equal_int,  intformeq_wf,  int_formula_prop_eq_lemma,  add_nat_wf,  false_wf,  equal_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  introduction,  cut,  lambdaFormation,  sqequalHypSubstitution,  productElimination,  thin,  extract_by_obid,  isectElimination,  hypothesisEquality,  hypothesis,  productEquality,  applyEquality,  because_Cache,  sqequalRule,  setElimination,  rename,  dependent_set_memberEquality,  addEquality,  natural_numberEquality,  dependent_functionElimination,  unionElimination,  independent_isectElimination,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  intEquality,  isect_memberEquality,  voidElimination,  voidEquality,  independent_pairFormation,  computeAll,  axiomEquality,  imageElimination,  equalityTransitivity,  equalitySymmetry,  applyLambdaEquality,  independent_functionElimination

Latex:
\mforall{}[n,x:\mBbbN{}].    (((t(x)  \mleq{}  n)  \mwedge{}  n  <  t(x  +  1))  {}\mRightarrow{}  (x  =  tsqrt(n)))



Date html generated: 2018_05_21-PM-07_54_20
Last ObjectModification: 2017_07_26-PM-05_31_54

Theory : general


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