Nuprl Lemma : bag-cases
∀[T:Type]. ∀bs:bag(T). ((bs = {} ∈ bag(T)) ∨ (↓∃x:T. ∃bs':bag(T). (bs = ({x} + bs') ∈ bag(T))))
Proof
Definitions occuring in Statement : 
bag-append: as + bs
, 
single-bag: {x}
, 
empty-bag: {}
, 
bag: bag(T)
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
or: P ∨ Q
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
nat: ℕ
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
uimplies: b supposing a
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
guard: {T}
, 
squash: ↓T
, 
exists: ∃x:A. B[x]
, 
bag-size: #(bs)
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
top: Top
, 
false: False
, 
cons: [a / b]
, 
single-bag: {x}
, 
bag-append: as + bs
, 
append: as @ bs
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
so_apply: x[s1;s2;s3]
Lemmas referenced : 
decidable__le, 
bag-size_wf, 
nat_wf, 
bag-size-zero, 
empty-bag_wf, 
squash_wf, 
exists_wf, 
bag_wf, 
equal_wf, 
bag-append_wf, 
single-bag_wf, 
bag_to_squash_list, 
not_wf, 
le_wf, 
list-cases, 
length_of_nil_lemma, 
satisfiable-full-omega-tt, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
product_subtype_list, 
length_of_cons_lemma, 
list-subtype-bag, 
list_ind_cons_lemma, 
list_ind_nil_lemma, 
cons_wf, 
equal-wf-T-base
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
isectElimination, 
cumulativity, 
hypothesisEquality, 
hypothesis, 
applyEquality, 
lambdaEquality, 
setElimination, 
rename, 
sqequalRule, 
natural_numberEquality, 
unionElimination, 
inlFormation, 
independent_isectElimination, 
inrFormation, 
imageElimination, 
productElimination, 
promote_hyp, 
equalitySymmetry, 
hyp_replacement, 
Error :applyLambdaEquality, 
because_Cache, 
dependent_pairFormation, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
hypothesis_subsumption, 
imageMemberEquality, 
baseClosed, 
universeEquality
Latex:
\mforall{}[T:Type].  \mforall{}bs:bag(T).  ((bs  =  \{\})  \mvee{}  (\mdownarrow{}\mexists{}x:T.  \mexists{}bs':bag(T).  (bs  =  (\{x\}  +  bs'))))
Date html generated:
2016_10_25-AM-10_22_26
Last ObjectModification:
2016_07_12-AM-06_39_07
Theory : bags
Home
Index