Adjacent, complementary, IF statements can occasionally be merged into an IF/THEN/ELSE block as follows:
IF (A(I) .GT. 0) B(I) = A(I) IF (A(I) .LE. 0) B(I) = B(I) - A(I)
Becomes:
IF (A(I) .GT. 0) THEN B(I) = A(I) ELSE B(I) = B(I) - A(I) ENDIF
