prefix NOT (p: BOOLEAN) : BOOLEAN
infix AND (p,q: BOOLEAN) : BOOLEAN
infix OR (p,q: BOOLEAN) : BOOLEAN
NOT p is the complement of p.
p AND q is TRUE if both p and q are TRUE. If p is FALSE, q is not evaluated.
p OR q is TRUE if at least one of p and q is TRUE. If p is TRUE, q is not evaluated.