Consider this function:
public static final int F(int a, int b) { a = a - 1 + b; // and some stuff return a; }
Is it required
Yes:
http://java.sun.com/docs/books/jls/third_edition/html/expressions.html#15.7
The JVM will intepret
x = input - 1 + q;
as
x = (input - 1) + q;