represent generalized members of the family of functions known as "hypergeometric". They are defined in terms of so-called "Mellin-Barnes integrals" as follows:
m,n
G
p,q
z
a
1
,…,
a
n
,
a
n+1
,…,
a
p
b
1
,…,
b
m
,
b
m+1
,…,
b
q
1
2π
∫
ℒ
m
∏
k=1
Γ(s+
b
k
)
n
∏
k=1
Γ(1-
a
k
-s)
p
∏
k=n+1
Γ(s+
a
k
)
q
∏
k=m+1
Γ(1-
b
k
-s)
-s
z
s
and
m,n
H
p,q
z
(
a
1
,
α
1
),…,(
a
n
,
α
n
)
,
(
a
n+1
,
α
n+1
),…,(
a
p
,
α
p
)
(
b
1
,
β
1
),…,(
b
m
,
β
m
)
,
(
b
m+1
,
β
m+1
),…,(
b
q
,
β
q
)
1
2π
∫
ℒ
m
∏
j=1
Γ
b
j
+
β
j
s
n
∏
i=1
Γ(1-
a
i
-
α
i
s)
p
∏
i=n+1
Γ(
a
i
+s
α
i
)
q
∏
j=m+1
Γ1-
b
j
-
β
j
s
-s
z
s
Notethat
m,n
H
p,q
reducesto
m,n
G
p,q
whenthe
α
i
areallequaltoone.
Much of the utility of these functions stems from the fact that a huge group of algebraic and special functions can be written as special cases of them when appropriate choices of the parameters are taken.