Searching for a pattern in a list

[invalid6363]

i'm trying to write a predicate that takes a list and a pattern and determines if the pattern exists in the list.
for example:

list = [r,r,b,g,y]
pattern = r,r

occurs([X,Y|_],X,Y).
occurs([_|L],X,Y) :- occurs(L,X,Y).

this kind of works for a pattern of two, but if the pattern is r,b the result would be false.
any suggestions on how to fix this would be greatly appreciated.
thank you.

 

[invalid6363]

this seems to work for a pattern of two:

occurs([X,Y|_],X,Y).
occurs([X|Y],X,Y).
occurs([_|L],X,Y) :- occurs(L,X,Y).

 

[invalid6363]

what about for a pattern of three?

i tried just simply adding another variable :

occurs([X,Y,Z|_],X,Y,Z).
occurs([_|L],X,Y,Z) :- occurs(L,X,Y,Z).

but this does not work at all.

any suggestions?