c(de+ed)*
cdeeded
ab*c(de+ed)*
acdeeded
ab*c(de+ed)*
aabbcdeeded
c({d}|{e})*
cddd
c({d}-{d,e})*
ce
c({d,e}-{d})*
ceeeee
aaaaabbbb
aaaaabbbb
a**
aaaaaa
((((a))+b))
b