CarryFrom
	Returns 1 if the addition specified as its parameter
caused a carry (true result is bigger than 232−1, where the
operands are treated as unsigned integers), and returns 0 in all
other cases. This delivers further information about an addition
which occurred earlier in the pseudo-code. The addition is not
repeated.


BorrowFrom
	Returns 1 if the subtraction specified as its parameter
caused a borrow (the true result is less than 0, where the
operands are treated as unsigned integers), and returns 0 in all
other cases. This delivers further information about a
subtraction which occurred earlier in the pseudo-code. The
subtraction is not repeated.


OverflowFrom
	Returns 1 if the addition or subtraction specified as its
parameter caused a 32-bit signed overflow. Addition generates an
overflow if both operands have the same sign (bit[31]), and the
sign of the result is different to the sign of both operands.
Subtraction causes an overflow if the operands have different
signs, and the first operand and the result have different signs.
This delivers further information about an addition or
subtraction which occurred earlier in the pseudo-code.  The
addition or subtraction is not repeated.

