Hi,
Generally, using nested IF/THENs produces less code than using AND. For example
Code:
IF A = 1 THEN
  IF B = 2 THEN
    IF C = 3 THEN
      IF D = 4 THEN
          IF E = 5 THEN
            HIGH PortB.0
          ENDIF
      ENDIF
    ENDIF
  ENDIF
ENDIF
Compiled for a 16F628 is 30 words and 76 bytes for 18F4520 (all variables are bytes) while using AND, like this
Code:
IF (A = 1) AND (B = 2) AND (C = 3) AND (D = 4) AND (E = 5) THEN
  HIGH PortB.0
ENDIF
takes 79 words for the 16F628 and 162 bytes for the 18F4520.

/Henrik.