I understand how to create "normal" tuplets in ABC: for example, where a triplet contains three notes, or a quintuplet contains five notes.
X:1 T:"Normal" Tuplets M:2/4 L:1/16 K:none (3A2A2A2 (5AAAAA
But I can't figure out how to do it if I want, say, a triplet with a quarter-note and an eighth note. Can ABC do that? How should it be coded?