On 07-Jun-1999, S.D.Mechveliani [EMAIL PROTECTED] wrote:
One more question on the program simplification and `bottom'.
People say, that the transformations like x - x - 0 :: Integer
are hardly ever applicable, because x may occur `undefined'.
This issue was already resolved --
On Mon, 7 Jun 1999, S.D.Mechveliani wrote:
One more question on the program simplification and `bottom'.
People say, that the transformations like x - x - 0 :: Integer
are hardly ever applicable, because x may occur `undefined'.
There is another problem lurking here as well.
One more question on the program simplification and `bottom'.
People say, that the transformations like x - x - 0 :: Integer
are hardly ever applicable, because x may occur `undefined'.
Say,
(let n = -n in n - n :: Integer) = undefined
But consider the program
f,f' ::
There is another problem lurking here as well. Namely space issues.
Consider the following program. It runs in constant space.
let xs = 1..n
x = head xs
in x - x + last xs + x
Now transforming it using
M - M - 0 and
0 + M - M
yields
let xs = 1..n
x = head xs
in last xs
