Use parenthese like:
IF (K=1) AND (A=FALSE) THEN BEGIN
(And on the other line the compiler barfs)
B.t.w.:
Again: do not write entire code in capitals.
(A=FALSE) is the same as not A. There is no need to compare a boolean with True or False. If that would be the case this would lead to comparisons at infinitum:
if (((((((((A=FALSE)=TRUE)=TRUE)=TRUE)=TRUE)=TRUE)=TRUE)=TRUE)=TRUE) ......
So, better do:
if (K=1) and not A then ...
Bart