Mine was "This deterministic approach has the advantage that migration of code from one imaginary symbol to another is as easy as: sed -e 's/k/l/' -e 's/j/k/'

Mine was "This deterministic approach has the advantage that migration of code from one imaginary symbol to another is as easy as: sed -e 's/k/l/' -e 's/j/k/' -e 's/i/j/' -e 's/l/i/' provided that you restrict yourself not to use the characters i, j, k or l in identifiers, keywords or strings in the source code."