fdo#72267 boolean_test is subsumed by general case "foo IS [NOT] bar"

Change-Id: Ie9666b1c8878dd26593629b4b64d74b7448f98c1
fdo#72391 empty formula is "rpt:", not starts with "rpt:"

(all?) functions start with rpt:
correction of erroneous cleanup wrt to equalsAsciiL

Change-Id: I0568ef28a1e677f68016b8593c2b30d0ffba1bb5