Common Lisp is a truly awful offender in this regard, with "cute" slightly-abbreviated opaque names for subtly-varying concepts.
EQ/EQL/EQUAL/EQUALP, PROCLAIM/DECLAIM/DECLARE, and the atrocious PAIRLIS (really??). And not to mention the fact that PAIRLIS returns an association list, which is entirely different from a "plist".
And then of course CAR, CDR, CADR, CDDR, et alia.
This is all second nature for an experienced Lisp programmer, but it makes for a difficult learning experience.
EQ/EQL/EQUAL/EQUALP, PROCLAIM/DECLAIM/DECLARE, and the atrocious PAIRLIS (really??). And not to mention the fact that PAIRLIS returns an association list, which is entirely different from a "plist".
And then of course CAR, CDR, CADR, CDDR, et alia.
This is all second nature for an experienced Lisp programmer, but it makes for a difficult learning experience.