On Monday, 27 January 2014 at 21:37:58 UTC, Ola Fosheim Grøstad
wrote:
On Monday, 27 January 2014 at 21:12:30 UTC, deadalnix wrote:
lolwut ? How do you make the difference between a program that
won't terminate ever and one that will terminate eventually
(say, in several years) ?
1. The halting problem does not apply to finite resources. The
proof is trivial: just record all state. You are in an infinite
loop when you revisit a state your program already has been in.
The halting problem only applies if you have non-finite storage.
2. You can set a timeout and use heurististics (and profiling)
for what computations you want to try to precompute. Perfectly
doable.
I don't think that is quite right, you can have an infinite loop
without there being any repeated states. Simple example is
for( i = 1; i>0 ; i++) {...}
This will run forever while still never repeating state, assuming
that i never wraps around. After all you said that we don't have
finite resources which is the same as saying we have unlimited
resources.
