Nuprl Lemma : code-coded-pair

∀n:ℕ. (let a,b = coded-pair(n) in code-pair(a;b) = n ∈ ℤ)


Proof




Definitions occuring in Statement :  code-pair: code-pair(a;b),  coded-pair: coded-pair(m),  nat: ℕ,  all: ∀x:A. B[x],  spread: spread def,  int: ℤ,  equal: s = t ∈ T
Definitions unfolded in proof :  all: ∀x:A. B[x],  code-pair: code-pair(a;b),  coded-pair: coded-pair(m),  member: t ∈ T,  uall: ∀[x:A]. B[x],  implies: P ⇒ Q,  has-value: (a)↓,  uimplies: b supposing a,  nat: ℕ,  so_lambda: λ2x.t[x],  so_apply: x[s],  subtype_rel: A ⊆r B,  prop: ℙ,  top: Top,  guard: {T},  ge: i ≥ j ,  decidable: Dec(P),  or: P ∨ Q,  satisfiable_int_formula: satisfiable_int_formula(fmla),  exists: ∃x:A. B[x],  false: False,  not: ¬A,  and: P ∧ Q,  subtract: n - m
Lemmas referenced :  tsqrt_wf,  nat_wf,  value-type-has-value,  set-value-type,  le_wf,  int-value-type,  subtract_wf,  triangular-num_wf,  equal_wf,  nat_properties,  decidable__le,  satisfiable-full-omega-tt,  intformand_wf,  intformnot_wf,  intformle_wf,  itermConstant_wf,  itermAdd_wf,  itermVar_wf,  itermMultiply_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_term_value_mul_lemma,  int_formula_prop_wf,  minus-add,  minus-minus,  add-associates,  minus-one-mul,  add-swap,  add-commutes,  add-mul-special,  zero-mul,  zero-add,  add-zero
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  lambdaFormation,  cut,  sqequalRule,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  thin,  hypothesisEquality,  hypothesis,  callbyvalueReduce,  independent_isectElimination,  intEquality,  lambdaEquality,  natural_numberEquality,  because_Cache,  equalityTransitivity,  equalitySymmetry,  setElimination,  rename,  applyEquality,  dependent_functionElimination,  independent_functionElimination,  isect_memberEquality,  voidElimination,  voidEquality,  dependent_set_memberEquality,  addEquality,  multiplyEquality,  minusEquality,  applyLambdaEquality,  unionElimination,  dependent_pairFormation,  int_eqEquality,  independent_pairFormation,  computeAll

Latex:
\mforall{}n:\mBbbN{}.  (let  a,b  =  coded-pair(n)  in  code-pair(a;b)  =  n)



Date html generated: 2018_05_21-PM-07_54_52
Last ObjectModification: 2017_07_26-PM-05_32_26

Theory : general


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