Nuprl Lemma : mod2-cases

∀x:ℤ. (((x mod 2) = 0 ∈ ℤ) ∨ ((x mod 2) = 1 ∈ ℤ))


Proof




Definitions occuring in Statement :  modulus: a mod n,  all: ∀x:A. B[x],  or: P ∨ Q,  natural_number: $n,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  subtract: n - m,  top: Top,  uiff: uiff(P;Q),  rev_implies: P ⇐ Q,  iff: P ⇐⇒ Q,  le: A ≤ B,  or: P ∨ Q,  decidable: Dec(P),  subtype_rel: A ⊆r B,  false: False,  guard: {T},  sq_type: SQType(T),  uimplies: b supposing a,  implies: P ⇒ Q,  not: ¬A,  nequal: a ≠ b ∈ T ,  int_nzero: ℤ-o,  prop: ℙ,  and: P ∧ Q,  true: True,  less_than': less_than'(a;b),  squash: ↓T,  less_than: a < b,  nat_plus: ℕ+,  member: t ∈ T,  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x]
Lemmas referenced :  less-iff-le,  or_wf,  le_antisymmetry_iff,  add-swap,  le-add-cancel2,  minus-zero,  minus-add,  add-commutes,  condition-implies-le,  le-add-cancel,  zero-add,  add-zero,  add-associates,  add_functionality_wrt_le,  not-equal-2,  false_wf,  equal_wf,  nequal_wf,  true_wf,  equal-wf-base,  int_subtype_base,  subtype_base_sq,  modulus_wf,  decidable__int_equal,  less_than_wf,  mod_bounds
Rules used in proof :  orFunctionality,  minusEquality,  voidEquality,  isect_memberEquality,  lambdaEquality,  addEquality,  inrFormation,  inlFormation,  unionElimination,  because_Cache,  applyEquality,  voidElimination,  independent_functionElimination,  equalitySymmetry,  equalityTransitivity,  independent_isectElimination,  intEquality,  cumulativity,  instantiate,  addLevel,  productElimination,  dependent_functionElimination,  hypothesis,  baseClosed,  imageMemberEquality,  independent_pairFormation,  sqequalRule,  natural_numberEquality,  dependent_set_memberEquality,  hypothesisEquality,  thin,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  introduction,  cut,  lambdaFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}x:\mBbbZ{}.  (((x  mod  2)  =  0)  \mvee{}  ((x  mod  2)  =  1))



Date html generated: 2020_05_19-PM-09_35_40
Last ObjectModification: 2019_12_16-PM-02_26_13

Theory : arithmetic


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