Nuprl Lemma : seq-tl-len

∀[T:Type]. ∀[s:sequence(T)].  ||seq-tl(s)|| ~ ||s|| - 1 supposing 0 < ||s||


Proof




Definitions occuring in Statement :  seq-tl: seq-tl(s),  seq-len: ||s||,  sequence: sequence(T),  less_than: a < b,  uimplies: b supposing a,  uall: ∀[x:A]. B[x],  subtract: n - m,  natural_number: $n,  universe: Type,  sqequal: s ~ t
Definitions unfolded in proof :  guard: {T},  sq_type: SQType(T),  true: True,  less_than': less_than'(a;b),  top: Top,  subtype_rel: A ⊆r B,  subtract: n - m,  uiff: uiff(P;Q),  prop: ℙ,  false: False,  implies: P ⇒ Q,  rev_implies: P ⇐ Q,  not: ¬A,  iff: P ⇐⇒ Q,  or: P ∨ Q,  decidable: Dec(P),  all: ∀x:A. B[x],  and: P ∧ Q,  le: A ≤ B,  pi1: fst(t),  seq-tl: seq-tl(s),  seq-len: ||s||,  sequence: sequence(T),  so_apply: x[s],  so_lambda: λ2x.t[x],  nat: ℕ,  uimplies: b supposing a,  member: t ∈ T,  uall: ∀[x:A]. B[x]
Lemmas referenced :  sequence_wf,  seq-len_wf,  less_than_wf,  le-add-cancel,  add-zero,  add_functionality_wrt_le,  add-commutes,  add-swap,  add-associates,  minus-minus,  minus-add,  minus-one-mul-top,  zero-add,  minus-one-mul,  condition-implies-le,  less-iff-le,  not-le-2,  false_wf,  decidable__le,  subtract_wf,  int_subtype_base,  le_wf,  set_subtype_base,  nat_wf,  subtype_base_sq
Rules used in proof :  universeEquality,  sqequalAxiom,  equalitySymmetry,  equalityTransitivity,  minusEquality,  because_Cache,  voidEquality,  isect_memberEquality,  applyEquality,  addEquality,  independent_functionElimination,  voidElimination,  lambdaFormation,  independent_pairFormation,  unionElimination,  dependent_functionElimination,  dependent_set_memberEquality,  rename,  setElimination,  productElimination,  hypothesisEquality,  natural_numberEquality,  lambdaEquality,  intEquality,  sqequalRule,  independent_isectElimination,  hypothesis,  cumulativity,  isectElimination,  sqequalHypSubstitution,  extract_by_obid,  instantiate,  thin,  cut,  introduction,  isect_memberFormation,  sqequalReflexivity,  computationStep,  sqequalTransitivity,  sqequalSubstitution

Latex:
\mforall{}[T:Type].  \mforall{}[s:sequence(T)].    ||seq-tl(s)||  \msim{}  ||s||  -  1  supposing  0  <  ||s||



Date html generated: 2018_07_25-PM-01_29_15
Last ObjectModification: 2018_06_17-PM-10_09_26

Theory : arithmetic


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