bag
dismantlable
set
Russell's paradox
brickety-brack
mass
position
place
multinumber
member
pile
cumulus
agglomerate
z-order
cumulation
palindrome
mound
heap
multiple
series
disjoint union
urelement
infinite sequence
anacoluthia
odd
cat's cradle
permutation
mechanism
co-recursively enumerable
hierarchically
class
tribrid
algebraic poset
axiom of regularity
cursor
slumgullion
double
intransitively
mathematical structure
motif
coatom
combination
atom
ennead
worldmate
right-side-up
base
classification scheme
paradox
alphabetical order
allotrope
Zorn's lemma
Tamari lattice
exception
compound
element
indexlike
permutation group
buffer
chirality
masquerade
accordion
basket
tramp
tertiary
third-class citizen
train
congeries
cardinal number
listing
axiom of countable choice
antimonotone
cardinal
third-class entity
recursively enumerable
scatter
nonempty
semiorder
basis
third-class value
heterogenous
playset
heterogeneous
sequency
medoid
visitor
algebraic structure
aggregation
nonelement
string
one-to-many
stabilizer subgroup
direct product
foreach loop
many-to-many
combinatorial
mixed bag