Nuprl Lemma : triangular-num-alt

∀[n:ℕ]. (t(n) = (((n ÷ 2) + (n rem 2)) * ((2 * (n ÷ 2)) + 1)) ∈ ℤ)


Proof




Definitions occuring in Statement :  triangular-num: t(n),  nat: ℕ,  uall: ∀[x:A]. B[x],  remainder: n rem m,  divide: n ÷ m,  multiply: 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,  nat: ℕ,  int_nzero: ℤ-o,  true: True,  nequal: a ≠ b ∈ T ,  not: ¬A,  implies: P ⇒ Q,  uimplies: b supposing a,  sq_type: SQType(T),  all: ∀x:A. B[x],  guard: {T},  false: False,  prop: ℙ,  nat_plus: ℕ+,  less_than: a < b,  squash: ↓T,  less_than': less_than'(a;b),  and: P ∧ Q,  triangular-num: t(n),  le: A ≤ B,  int_seg: {i..j-},  lelt: i ≤ j < k,  subtype_rel: A ⊆r B,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  decidable: Dec(P),  or: P ∨ Q,  top: Top,  ge: i ≥ j ,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  so_lambda: λ2x.t[x],  so_apply: x[s]
Lemmas referenced :  div_rem_sum,  subtype_base_sq,  int_subtype_base,  equal-wf-base,  true_wf,  nequal_wf,  rem_bounds_1,  less_than_wf,  nat_wf,  divide_wf,  lelt_wf,  int_seg_wf,  equal_wf,  squash_wf,  add_functionality_wrt_eq,  iff_weakening_equal,  decidable__equal_int,  mul-distributes,  mul-distributes-right,  mul-associates,  add-associates,  mul-swap,  mul-commutes,  zero-mul,  zero-add,  add-zero,  one-mul,  add-commutes,  div-cancel,  int_seg_properties,  nat_properties,  satisfiable-full-omega-tt,  intformnot_wf,  intformeq_wf,  itermAdd_wf,  itermMultiply_wf,  itermConstant_wf,  itermVar_wf,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_add_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_formula_prop_wf,  set_subtype_base,  intformand_wf,  intformless_wf,  intformle_wf,  int_formula_prop_and_lemma,  int_formula_prop_less_lemma,  int_formula_prop_le_lemma,  decidable__le,  decidable__lt,  add-swap,  add-mul-special
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  setElimination,  rename,  hypothesisEquality,  hypothesis,  dependent_set_memberEquality,  natural_numberEquality,  addLevel,  lambdaFormation,  instantiate,  cumulativity,  intEquality,  independent_isectElimination,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  voidElimination,  baseClosed,  sqequalRule,  independent_pairFormation,  imageMemberEquality,  productElimination,  because_Cache,  multiplyEquality,  addEquality,  divideEquality,  applyEquality,  lambdaEquality,  imageElimination,  universeEquality,  unionElimination,  isect_memberEquality,  voidEquality,  dependent_pairFormation,  int_eqEquality,  computeAll

Latex:
\mforall{}[n:\mBbbN{}].  (t(n)  =  (((n  \mdiv{}  2)  +  (n  rem  2))  *  ((2  *  (n  \mdiv{}  2))  +  1)))



Date html generated: 2019_06_20-PM-02_37_57
Last ObjectModification: 2019_06_12-PM-00_26_29

Theory : num_thy_1


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