Nuprl Lemma : firstn_nth_tl
∀[T:Type]. ∀[L:T List]. ∀[i:ℕ]. (L ~ firstn(i;L) @ nth_tl(i;L))
Proof
Definitions occuring in Statement :
firstn: firstn(n;as),
nth_tl: nth_tl(n;as),
append: as @ bs,
list: T List,
nat: ℕ,
uall: ∀[x:A]. B[x],
universe: Type,
sqequal: s ~ t
Definitions unfolded in proof :
uall: ∀[x:A]. B[x],
member: t ∈ T,
all: ∀x:A. B[x],
nat: ℕ,
decidable: Dec(P),
or: P ∨ Q,
int_seg: {i..j-},
lelt: i ≤ j < k,
and: P ∧ Q,
le: A ≤ B,
prop: ℙ,
uimplies: b supposing a,
subtype_rel: A ⊆r B,
top: Top,
ge: i ≥ j ,
satisfiable_int_formula: satisfiable_int_formula(fmla),
exists: ∃x:A. B[x],
false: False,
implies: P ⇒ Q,
not: ¬A,
append: as @ bs,
so_lambda: so_lambda(x,y,z.t[x; y; z]),
so_apply: x[s1;s2;s3]
Lemmas referenced :
list_ind_nil_lemma,
list_ind_cons_lemma,
list_wf,
nat_wf,
append_back_nil,
nth_tl_is_nil,
int_formula_prop_wf,
int_formula_prop_less_lemma,
int_term_value_var_lemma,
int_formula_prop_le_lemma,
int_formula_prop_not_lemma,
int_formula_prop_and_lemma,
intformless_wf,
itermVar_wf,
intformle_wf,
intformnot_wf,
intformand_wf,
satisfiable-full-omega-tt,
decidable__le,
nat_properties,
top_wf,
subtype_rel_list,
firstn_all,
nth_tl_decomp,
lelt_wf,
firstn_nth_tl_decomp,
length_wf,
decidable__lt
Rules used in proof :
sqequalSubstitution,
sqequalTransitivity,
computationStep,
sqequalReflexivity,
isect_memberFormation,
introduction,
cut,
lemma_by_obid,
sqequalHypSubstitution,
dependent_functionElimination,
thin,
setElimination,
rename,
hypothesisEquality,
isectElimination,
hypothesis,
unionElimination,
dependent_set_memberEquality,
independent_pairFormation,
productElimination,
cumulativity,
sqequalRule,
because_Cache,
independent_isectElimination,
applyEquality,
lambdaEquality,
isect_memberEquality,
voidElimination,
voidEquality,
natural_numberEquality,
dependent_pairFormation,
int_eqEquality,
intEquality,
computeAll,
sqequalAxiom,
universeEquality
Latex:
\mforall{}[T:Type]. \mforall{}[L:T List]. \mforall{}[i:\mBbbN{}]. (L \msim{} firstn(i;L) @ nth\_tl(i;L))
Date html generated:
2016_05_14-PM-02_08_15
Last ObjectModification:
2016_01_15-AM-08_02_01
Theory : list_1
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