en_partut-ud-1610.conllu

# sent_id = en_partut-ud-1610
# text = they were unimpressed.
1	they	they	PRON	PE	Number=Plur|Person=3|PronType=Prs	3	nsubj	_	_
2	were	be	AUX	V	Mood=Ind|Number=Plur|Tense=Past|VerbForm=Fin	3	cop	_	_
3	unimpressed	unimpressed	ADJ	A	Degree=Pos	0	root	_	SpaceAfter=No
4	.	.	PUNCT	FS	_	3	punct	_	_

test.grs

rule add_token_feature {
  pattern { N [ lemma ]; }
  without { N [ token ]; }
  commands { N.token = N.lemma; }
}

strat main { Onf (add_token_feature) }