posit subtraction fixed

[Akshanshkaushal]

This PR fixes a bug in the posit subtraction operation closes #10

[Mark1626]

Thanks for taking the time to look into this issue. However, the proposed fix doesn’t actually resolve the underlying problem—it just bypasses it with a conditional check. While this may appear to "work" in a narrow case, it doesn’t address the root cause and could lead to unexpected behavior elsewhere.

If you’d like to work on this, I’d encourage you to dig deeper into why the bug occurs and propose a solution that properly fixes the logic rather than working around it. Please revise the PR with a more robust fix, or if you’re unable to do so, we can reassign the issue. Looking forward to your updates!