Nuprl Lemma : append-impossible2
∀[T:Type]. ∀[as,bs,cs:T List].  ∀[b:T]. uiff(cs = (as @ [b / bs]) ∈ (T List);False) supposing cs ≤ as
Proof
Definitions occuring in Statement : 
iseg: l1 ≤ l2
, 
append: as @ bs
, 
cons: [a / b]
, 
list: T List
, 
uiff: uiff(P;Q)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
false: False
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
false: False
, 
prop: ℙ
, 
squash: ↓T
, 
subtype_rel: A ⊆r B
, 
top: Top
, 
le: A ≤ B
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
ge: i ≥ j 
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
not: ¬A
Lemmas referenced : 
iseg_length, 
le_wf, 
length_wf, 
squash_wf, 
true_wf, 
length_append, 
subtype_rel_list, 
top_wf, 
cons_wf, 
iff_weakening_equal, 
length_of_cons_lemma, 
non_neg_length, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformle_wf, 
itermConstant_wf, 
itermVar_wf, 
itermAdd_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_var_lemma, 
int_term_value_add_lemma, 
int_formula_prop_wf, 
equal_wf, 
list_wf, 
append_wf, 
false_wf, 
iseg_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
because_Cache, 
hypothesisEquality, 
independent_isectElimination, 
hypothesis, 
equalitySymmetry, 
hyp_replacement, 
Error :applyLambdaEquality, 
cumulativity, 
sqequalRule, 
applyEquality, 
lambdaEquality, 
imageElimination, 
equalityTransitivity, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
productElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
independent_functionElimination, 
dependent_functionElimination, 
dependent_pairFormation, 
int_eqEquality, 
computeAll, 
independent_pairEquality, 
axiomEquality
Latex:
\mforall{}[T:Type].  \mforall{}[as,bs,cs:T  List].    \mforall{}[b:T].  uiff(cs  =  (as  @  [b  /  bs]);False)  supposing  cs  \mleq{}  as
Date html generated:
2016_10_25-AM-10_16_33
Last ObjectModification:
2016_07_12-AM-06_35_05
Theory : list!
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