The well-known pumping lemma for regular languages states that, for any regular language L, there is a constant p (depending on L) such that the following holds: If $$w\in L$$
w
∈
L
and $$\vert w\vert \ge p$$
|
w
|
≥
p
, then there are words $$x\in V^{*}$$
x
∈
V
∗
, $$y\in V^+$$
y
∈
V
+
, and $$z\in V^{*}$$
z
∈
V
∗
such that $$w=xyz$$
w
=
x
y
z
and $$xy^tz\in L$$
x
y
t
z
∈
L
for $$t\ge 0$$
t
≥
0
. The minimal pumping constant $${{{\,\mathrm{mpc}\,}}(L)}$$
mpc
(
L
)
of L is the minimal number p for which the conditions of the pumping lemma are satisfied. We investigate the behaviour of $${{{\,\mathrm{mpc}\,}}}$$
mpc
with respect to operations, i. e., for an n-ary regularity preserving operation $$\circ $$
∘
, we study the set $${g_{\circ }^{{{\,\mathrm{mpc}\,}}}(k_1,k_2,\ldots ,k_n)}$$
g
∘
mpc
(
k
1
,
k
2
,
…
,
k
n
)
of all numbers k such that there are regular languages $$L_1,L_2,\ldots ,L_n$$
L
1
,
L
2
,
…
,
L
n
with $${{{\,\mathrm{mpc}\,}}(L_i)=k_i}$$
mpc
(
L
i
)
=
k
i
for $$1\le i\le n$$
1
≤
i
≤
n
and $${{{\,\mathrm{mpc}\,}}(\circ (L_1,L_2,\ldots ,L_n)=~k}$$
mpc
(
∘
(
L
1
,
L
2
,
…
,
L
n
)
=
k
. With respect to Kleene closure, complement, reversal, prefix and suffix-closure, circular shift, union, intersection, set-subtraction, symmetric difference,and concatenation, we determine $${g_{\circ }^{{{\,\mathrm{mpc}\,}}}(k_1,k_2,\ldots ,k_n)}$$
g
∘
mpc
(
k
1
,
k
2
,
…
,
k
n
)
completely. Furthermore, we give some results with respect to the minimal pumping length where, in addition, $$\vert xy\vert \le p$$
|
x
y
|
≤
p
has to hold.