Nuprl Lemma : twice-triangular

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


Proof




Definitions occuring in Statement :  triangular-num: t(n),  nat: ℕ,  uall: ∀[x:A]. B[x],  multiply: n * m,  add: n + m,  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  triangular-num: t(n),  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,  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  uiff: uiff(P;Q),  and: P ∧ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  top: Top,  squash: ↓T,  nat_plus: ℕ+,  less_than: a < b,  less_than': less_than'(a;b),  subtype_rel: A ⊆r B,  iff: P ⇐⇒ Q,  rev_implies: P ⇐ Q,  subtract: n - m,  bool: 𝔹,  unit: Unit,  it: ⋅,  btrue: tt,  ifthenelse: if b then t else f fi ,  bfalse: ff,  bnot: ¬bb,  assert: ↑b
Lemmas referenced :  div_rem_sum,  subtype_base_sq,  int_subtype_base,  equal-wf-base,  true_wf,  nequal_wf,  nat_properties,  decidable__equal_int,  add-is-int-iff,  multiply-is-int-iff,  full-omega-unsat,  intformand_wf,  intformnot_wf,  intformeq_wf,  itermMultiply_wf,  itermConstant_wf,  itermVar_wf,  itermAdd_wf,  int_formula_prop_and_lemma,  int_formula_prop_not_lemma,  int_formula_prop_eq_lemma,  int_term_value_mul_lemma,  int_term_value_constant_lemma,  int_term_value_var_lemma,  int_term_value_add_lemma,  int_formula_prop_wf,  false_wf,  nat_wf,  equal_wf,  rem_mul,  decidable__le,  intformle_wf,  int_formula_prop_le_lemma,  le_wf,  less_than_wf,  iff_weakening_equal,  rem_add1,  eq_int_wf,  bool_wf,  eqtt_to_assert,  assert_of_eq_int,  rem_base_case,  decidable__lt,  intformless_wf,  int_formula_prop_less_lemma,  zero_ann,  eqff_to_assert,  bool_cases_sqequal,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  rem_bounds_1
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  isect_memberFormation,  cut,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  multiplyEquality,  setElimination,  rename,  hypothesisEquality,  hypothesis,  addEquality,  because_Cache,  natural_numberEquality,  dependent_set_memberEquality,  addLevel,  lambdaFormation,  instantiate,  cumulativity,  intEquality,  independent_isectElimination,  dependent_functionElimination,  equalityTransitivity,  equalitySymmetry,  independent_functionElimination,  voidElimination,  baseClosed,  unionElimination,  pointwiseFunctionality,  promote_hyp,  sqequalRule,  baseApply,  closedConclusion,  productElimination,  approximateComputation,  dependent_pairFormation,  lambdaEquality,  int_eqEquality,  isect_memberEquality,  voidEquality,  independent_pairFormation,  applyEquality,  imageElimination,  imageMemberEquality,  remainderEquality,  equalityElimination

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



Date html generated: 2018_05_21-PM-07_53_47
Last ObjectModification: 2018_05_19-PM-04_52_27

Theory : general


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