tuple -tup-tu'e- gismu

x1 is a/the leg [body-part] of x2; [metaphor: supporting branch].

See also stani, zbepi, jamfu, jimca, sanli.

On gloss:

orsi in sense "n-tuple, where n is non-negative integer or (countable) infinity"
x1 is an ordered tuple/sequence of x2 (li) members, namely x3, x4, x5 ...

In definition:

nomei (comp!)
x1 is a 0-some / empty mass / 0-tuple, with members x2 (must be the empty set).
taknyklojyzilpra
x1 is the transitive closure (directed graph/set of ordered 2-tuples/space) derived/produced/induced from relation space x2.
grafu
x1 is the graph on vertices/nodes x2 (set) and edges x3 (set of ordered or unordered 2-tuples of vertices in x2) and with additional properties x4.
bai'i (exp!)
mekso string operator (ternary): find-and-replace; in string/text/word/sequence X1 formally replace X2 (ordered tuple of terms to be replaced) with X3 (ordered tuple of terms to be respectively substituted)
bai'i'i (exp!)
mekso operator: in ordered tuple/list/vector/sequence X1, replace the X2th entry with term X3 of appropriate type, and leave all other entries untouched (optional: where the index for the very first/leading/header entry is X4).
ce'ei'oi
BIhI argument modifier: indicates dimensionality/length of tuple
ci'au'i (exp!)
mekso at-most-4-ary operator: integer lattice ball; the set of all points belonging to the intersection of Zn with the closure of the ball that is centered on X1 and has radius X2 in metric X3, where Z is the set of all integers and where, for any set A and non-negative integer n, An is the set of all n-tuples such that each coordinate/entry/term belongs to A, and where the dimensionality n = X4..
ci'o'au (exp!)
mekso operator (binary): projection function; the Bth term/entry ("element") of tuple A
du'a'e (exp!)
mekso n-ary ordered operator: structure creator/ordered tuple, 'endow'; the structure formed by underlying set X1 (as) endowed with element, order, quoted operator, etc. X2, X3, ...
du'a'o (exp!)
mekso binary operator: extract substructure/underlying set/endowing operator; the substructure (general sense; includes just operator, order, set, etc.) of X1 (structure; explicitly given by {du'a'e}) which is formed by collecting the ith entries of that {du'a'e}-tuple in order together into their own {du'a'e}-tuple (or by extracting them naked into the ambient environment if X2 is a singleton) for all i in set X2
fa'ai'ai (exp!)
mekso k-ary operator, for natural k and 1 < k < 5: ordered input (f, g, S, m) where f and g are functions, S is a set of positive integers or "ro" (="all"), and m is 0 or 1 (as a toggle); output is a function equivalent to the function f as applied to an input ordered tuple with g applied to the entries/terms with indices in S (or to all entries/terms if S="ro") if m=0, or g left-composed with the same if m=1.
fa'ei
Unary mekso operator: reverse finite ordered sequence, tuple, list, string, etc.
mai'u'ei (exp!)
mekso unary operator: Levi-Civita symbol; for input n-tuple (a1, a ... , an), where n is a strictly positive integer, the output is \varepsilona, where \varepsilon is the Levi-Civita symbol under the convention of mapping (1, 2, ..., n) to 1.
pi'au'e (exp!)
mekso ternary operator: extract digit from number; X2nd macrodigit/term of number/tuple X1 when X1 is expressed in base/basis X3.
pi'u'e (exp!)
mekso n-ary operator: generate ordered tuple/list from inputs; pi'u'e(x1, x= (x1, x, pi'u'e(x1, x= (x1, x, etc.
vau'e'oi
interval bracket ordered tuple introducer
vau'o'oi
interval bracket ordered tuple terminator
ze'ai'au
unary mekso operator: reverse ordered list/tuple X1.
faumji
x1 is the result of evaluating mathematical object x2 at point/with input value x3 (ordered tuple)
grafetu
x1 is the graph on vertices/nodes x2 (set) and edges x3 (set of ordered or unordered tuples of vertices in x2) and with additional properties x4.
grafnseljimca
x1 is a tree graph on nodes x2 (set of points), with edges x3 (set of ordered or unordered 2-tuples), with additional properties x4.
kaunmei
x1 (collection, body, set, mass, tuple, n-some, etc.) is x2 (li; default: 1) indivisible/atomic/elementary/basic discrete entities (or particles) of type x3 in composition/content, by standard x4; the count of instances of x3 in x1 is x2 by standard x4.
setxeve
x1 (predicate, relation, function, set of n-tuples) is the converse/conversion/complement/transpose/commutation/functional-'permutation' of x2 (same typing as x1), as defined on set/object/space/graph x4, with argument/input slots permuted via function/operator/marker/permutation/(group) action x3.
si'impetotki
x1 (value, state, form) is the asymptote/limit [Calculus sense] of function/dependent variable/limitand x2 as independent variable(s) x3 tend(s) toward point/respective value(s)/tuple x4 along path/from direction x5.
vinzoru
x1 (set of tuples) is the x4-Winsorized data formed from data set x2 (set of tuples), Winsorizing with respect to variable x3.

In notes:

jamfu
x1 is a/the foot [body-part] of x2; [metaphor: lowest portion] (adjective:) x1 is pedal.
jimca
x1 is a branch/bough/limb of x2; x2 forks into branches x1; [preferred over metaphorical birka].
sanli
x1 stands [is vertically oriented] on surface x2 supported by limbs/support/pedestal x3.
stani
x1 is a/the stalk/stem/trunk [body-part] of plant/species x2; [metaphor: main support].
zbepi
x1 is a pedestal/base/stand/pallet supporting x2 (object/event), of materials/properties x3.
mei
convert number to cardinality selbri; x1 is a mass formed from a set x2 of n members, one or more of which is/are x3, measured relative to the set x4.
cibyseltu'e
t2 is three-legged with legs t1.
galtupcra
c1=g1 is the lap of t2.
ki'irgrafu
x1 is a relation space formed from elements/nodes in set x2 and relationship x3 which connects them.
relseltu'e
t2 is two-legged with legs t1.
terbri
x1 (sequence of sumti) is the sequence of arguments that, joined by relation x2 (ka), form predicate x3 (du'u)
terdzu
x3=c1 walks/strides/paces on surface x2=c2 using limbs x1=c3.
tsetupyzbe
t1=zb1 is a lap [body part] of t2=zu1 supporting zb2.
vonseltu'e
t2 is four-legged with legs t1.
zaglamtu'e
t1 is the thigh of t2=z2.
tubra
x1 is a limb/appendage/extremity of body/entity x2 used for purpose x3
fa'ai (exp!)
mathematical ordered n-ary operator: (pointwise) functional left composition; X1 \circ X.
fa'au (exp!)
mathematical unary operator: map notation
fau'e (exp!)
iterated function left-composition with self: f∘f∘...∘f, n times.
fi'au
mekso operator: continued fraction, Kettenbruch notation; for ordered input (X1, X, where: X1 is an ordered pair of functions and X2 is a free or dummy variable/input/index which ranges through set X3 in order(ing) X4, the result is K(X for Kettenbruch notation K.
jau'au (exp!)
unary mathematical operator: length/number of components/terms of/in object/array/formal string/sequence/word/text in some alphabet/base/basis which includes each digit; number of digits/components/entries
ka'o'ai (exp!)
imaginary i (non-comma)
kau'u
Predicate to variable-binding binary quantifier. The first slot of the predicate must be a property.
kei'ai (exp!)
mekso style converter: elementwise application of operator
moi'u (exp!)
x1 is (n)th member of alphabet/set x2 ordered by rule x3, where the count begins at x4.
re'ai'e
free conversion
se'ai'e (exp!)
(n, 1, 2, \dots, n-2, n - 1)st conversion.
se'au'e (exp!)
(2, 3, \dots, n-1, n, 1)st conversion.
se'u'o (exp!)
selbri conversion question
to'ei'au (exp!)
binary mathematical operator: Jordan totient function Ja(b)
djeisone
x1 is an object described as x2, x3, ... (termset representing serializable tree structure compatible with JSON format of attribute-value pairs).
klojere
x1 (set/space) is closed under operator/relation x2; x2 has closure in x1.
tentaku
x1 is a tentacle