Nuprl Lemma : rel-comp-exp

∀[T:Type]. ∀[R,S:T ⟶ T ⟶ ℙ].  ∀n:ℕ. (R o S)^n ⇐⇒ if (n =z 0) then λx,y. (x = y ∈ T) else (R o ((S o R)^n - 1 o S)) fi\000C 


Proof




Definitions occuring in Statement :  rel-comp: (R1 o R2),  rel_equivalent: R1 ⇐⇒ R2,  rel_exp: R^n,  nat: ℕ,  ifthenelse: if b then t else f fi ,  eq_int: (i =z j),  uall: ∀[x:A]. B[x],  prop: ℙ,  all: ∀x:A. B[x],  lambda: λx.A[x],  function: x:A ⟶ B[x],  subtract: n - m,  natural_number: $n,  universe: Type,  equal: s = t ∈ T
Definitions unfolded in proof :  uall: ∀[x:A]. B[x],  all: ∀x:A. B[x],  rel_exp: R^n,  eq_int: (i =z j),  subtract: n - m,  ifthenelse: if b then t else f fi ,  btrue: tt,  implies: P ⇒ Q,  member: t ∈ T,  nat: ℕ,  and: P ∧ Q,  less_than: a < b,  squash: ↓T,  cand: A c∧ B,  decidable: Dec(P),  or: P ∨ Q,  iff: P ⇐⇒ Q,  not: ¬A,  rev_implies: P ⇐ Q,  false: False,  uiff: uiff(P;Q),  uimplies: b supposing a,  top: Top,  le: A ≤ B,  less_than': less_than'(a;b),  true: True,  bool: 𝔹,  unit: Unit,  it: ⋅,  bfalse: ff,  exists: ∃x:A. B[x],  sq_type: SQType(T),  guard: {T},  bnot: ¬bb,  assert: ↑b,  nequal: a ≠ b ∈ T ,  prop: ℙ,  so_lambda: λ2x.t[x],  ge: i ≥ j ,  int_upper: {i...},  subtype_rel: A ⊆r B,  sq_stable: SqStable(P),  so_apply: x[s],  rel_equivalent: R1 ⇐⇒ R2,  infix_ap: x f y,  rel-comp: (R1 o R2)
Lemmas referenced :  rel_equivalent_wf,  rel_exp_wf,  subtract_wf,  decidable__le,  istype-false,  not-le-2,  less-iff-le,  condition-implies-le,  minus-one-mul,  zero-add,  minus-one-mul-top,  istype-void,  minus-add,  minus-minus,  add-associates,  add-swap,  add-commutes,  add_functionality_wrt_le,  add-zero,  le-add-cancel,  istype-le,  rel-comp_wf,  eq_int_wf,  eqtt_to_assert,  assert_of_eq_int,  equal_wf,  eqff_to_assert,  bool_cases_sqequal,  subtype_base_sq,  bool_wf,  bool_subtype_base,  assert-bnot,  neg_assert_of_eq_int,  not-equal-2,  minus-zero,  le-add-cancel-alt,  istype-int,  istype-less_than,  primrec-wf2,  upper_subtype_nat,  nat_properties,  nequal-le-implies,  sq_stable__le,  istype-nat,  istype-universe,  less_than_transitivity1,  le_weakening,  less_than_irreflexivity,  subtype_rel_self,  le-add-cancel2,  infix_ap_wf
Rules used in proof :  sqequalSubstitution,  sqequalTransitivity,  computationStep,  sqequalReflexivity,  Error :isect_memberFormation_alt,  Error :lambdaFormation_alt,  cut,  thin,  sqequalRule,  rename,  setElimination,  Error :universeIsType,  introduction,  extract_by_obid,  sqequalHypSubstitution,  isectElimination,  hypothesisEquality,  Error :dependent_set_memberEquality_alt,  natural_numberEquality,  hypothesis,  independent_pairFormation,  imageElimination,  productElimination,  dependent_functionElimination,  unionElimination,  voidElimination,  independent_functionElimination,  independent_isectElimination,  addEquality,  Error :isect_memberEquality_alt,  minusEquality,  because_Cache,  closedConclusion,  Error :inhabitedIsType,  equalityElimination,  Error :lambdaEquality_alt,  equalityTransitivity,  equalitySymmetry,  Error :dependent_pairFormation_alt,  Error :equalityIstype,  promote_hyp,  instantiate,  cumulativity,  Error :setIsType,  hypothesis_subsumption,  applyEquality,  imageMemberEquality,  baseClosed,  Error :functionIsType,  universeEquality,  independent_pairEquality,  axiomEquality,  Error :functionIsTypeImplies,  Error :productIsType,  hyp_replacement,  applyLambdaEquality,  productEquality

Latex:
\mforall{}[T:Type].  \mforall{}[R,S:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}n:\mBbbN{}.  (R  o  S)\^{}n  \mLeftarrow{}{}\mRightarrow{}  if  (n  =\msubz{}  0)  then  \mlambda{}x,y.  (x  =  y)  else  (R  o  (rel\_exp(T;  (S  o  R);  n  -  1)  o  S))  fi 



Date html generated: 2019_06_20-PM-00_31_22
Last ObjectModification: 2019_03_27-PM-01_28_36

Theory : relations


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