Input line expression editor failure

[alainarasti]

This might be caused by how certain calculators or software handle input editing after an expression is copied from the history. When an operation like (-1/2)^2 is copied the system often locks the fraction into a noneditable form due to internal formatting rules. This prevents placing the cursor either inside or outside the fraction for additional edits. A potential workaround is to manually re-enter the fraction rather than copying it from the history. Alternatively make sure you’re using parentheses in a way that avoids such formatting conflicts, likr:
Write (-1/2) directly again instead of copying it.
Use a text-based input mode if available where the cursor can move freely.