Why do miniKanren names always end with `o`?

Question

All miniKanren relations end with the letter o. What is the motivation for this? I see that the Clojure core.logic library also does this.

score 12 · Accepted Answer · answered Feb 06 '12 at 18:48

12

In the Preface of The Reasoned Schemer, they explain it thus:

A relation, a function that returns a goal as its value, ends its name with a superscript 'o' (e.g., car^o and null^o).

So, it's a notation to denote a relation.

answered Feb 06 '12 at 18:48

C. K. Young

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score 5 · Answer 2 · answered Feb 08 '12 at 17:51

It's because the authors of The Reasoned Schemer wanted the notation of miniKanren relations to be evocative of ordinary Scheme predicates which end in ? (e.g., null?, pair?) by convention. The superscript ^o, if you squint enough (and have heard this story before), looks like a modified ?.

Why do miniKanren names always end with `o`?

2 Answers2