Dear all, since the current behavior for
all functions is override series(int_lag)
behavior. A possible solution would be

1) for series(int1 to int2)
to protect it from functions, since int1 to int2
can be distinguished from functions arguments
2) for series(int) in each call (for coinciding names only)
type warning:

series(int) has been interpreted as function call
rename series if you want obtain its lags

This way the current behavior will be retained for
series(int) the only thing to do is give more info
Once more, the syntax series(int1 to int2) is
separable from function calls