How to braise lettuce<br>Prepare the lettuce. First take sweet romaine lettuce and discard any wilting or unhealthy looking leaves. Using a sharp knife, cut ½ of stem off the lettuce.
Using a dull knife to cut off the stem of the lettuce is ok.
it doesn't say if it's ok or not so it should be neither but the passage only says sharp so the AI marked it incorrect.
( z1 okay :ARG1 ( z2 use :ARG1 ( z3 knife :ARG1-of ( z4 dull ) ) :ARG2 ( z5 cut-off :ARG1 ( z6 stem :part-of ( z7 lettuce ) ) ) ) )