Do primary/scholarly sources confirm that Mekh-mat's 'coffin problems' were deliberately unsolvable problems used to fail Jewish applicants?

The claim-note claim-mekh-mat-coffin-problems-used-to-fail-jewish-applicants rests only on Tier-4 material (the Wikipedia article "Antisemitism in Soviet mathematics" and YIVO-derived summaries) as carried by the capture. The existence of hard oral entrance problems is uncontested, but the load-bearing, potentially contested part — that specific problems were deliberately constructed to be practically unsolvable and were selectively deployed to fail Jewish and other undesired applicants at Moscow State University's Faculty of Mechanics and Mathematics — is a discrimination-mechanism claim that the sourcing floor says should clear Tier 1–2, not sit on an aggregator.

Why it matters. This is the institutional-admissions counterpart to the individual-exclusion story in claim-pontryagin-used-committee-vote-to-help-block-margulis-1978-fields-medal-travel; together they anchor a possible antisemitism-in-Soviet-mathematics cluster. If the "deliberate / selective" framing is overstated, the note needs softening.

What would answer it:

1. Pull the standard scholarly treatments, which are strong and specific: A. Vershik and A. Shen's writing on the topic; the AMS Notices article on the entrance examinations (Vershik, "Admission to the Mathematics Faculty in Russia in the 1970s and 1980s"); T. Khovanova & A. Radul, "Killer Problems" / the "Coffins" problem set; and M. Shifman's collection You Failed Your Math Test, Comrade Einstein. Confirm the "deliberately unsolvable" and "selectively applied" characterizations with named testimony and example problems.
2. Replace the Tier-4 provenance on the note with a Tier 1–2 source and a verbatim quote once located; if the scholarly record qualifies the "deliberate" claim, revise the note's wording accordingly.
3. Check scope — whether the practice is documented specifically at MSU Mekh-mat (as the note states) versus generalized across institutions.