Mateo Delacroix’s “Proof of Residency,” which opened last week at The Silt Lab, is running at about eighty percent of what it’s attempting — and what it’s attempting is formally demanding enough that eighty percent is worth sitting on a folding chair in the East Village for ninety minutes.

The play takes place in the waiting room of an unnamed municipal licensing office, over one afternoon, with a family of three waiting for an appointment that keeps not materializing. Delacroix gives us this setup once, then returns to it — not with the same words, but with the same architecture — and each pass chips something away from the certainty of what we thought we understood. By the third iteration you are watching what appears to be the same family in what is obviously no longer the same situation, and the difference between those two readings is the thing the play is actually about.

This is a device that belongs to a particular theatrical tradition: the repetition-with-variation grammar that Suzan-Lori Parks worked through in her early plays, and that Anne Washburn built the structural bones of “Mr. Burns” from. Delacroix is working consciously in that lineage — you can feel the formal inheritance — but the application is his own. Where Parks used repetition as a kind of spell, accumulating meaning through sonic and structural return, Delacroix uses it as erosion. Each pass removes a layer of confidence from the audience’s position. You stop trusting your memory of the first pass, which is exactly the point, because the characters onstage are losing that kind of certainty too.

June Oshiro’s direction is correct in almost every way that direction can be correct for a piece like this. She does not signal the transitions. There is no light shift, no musical cue, no moment where the production winks at you and says: this is a new pass. Each version begins as though it is simply the next scene, and you have to catch the variation yourself, calibrate against what you remember, and decide what the difference means. That is the right call. A less confident director would have lit the thresholds. Oshiro doesn’t.

The three performers — Aminata Sow, Kwesi Agyeman, and Perla Morales-Kim — are doing technically precise work. Sow in particular holds a quality across all four iterations that I kept watching: she is the same person in ways that are clearly about character, and also changed in ways that are clearly about what the repetition has done to her, and she holds both without announcement. That is a difficult set of instructions to follow. She follows them.

Where Delacroix loses the structure is in the fourth pass, which wants to be a resolution the form doesn’t support. The first three iterations earn their ambiguity — they trust the audience to feel what’s accumulating without naming it. The fourth reaches for a specific grief, a named arrival, and the play’s own logic has spent eighty minutes working against the possibility of arrival. It lands. But it lands softer than the architecture deserved, and you feel the playwright overriding his structure rather than completing it. That is a different problem than not finishing — it is the problem of finishing in the wrong key.

This is still a world premiere worth your attention. Delacroix has found a formal grammar for a particular kind of institutional waiting — the specific psychic texture of being made to prove something about yourself to a system that does not actually want to know — and three passes of that is worth more than most complete plays running downtown right now.