1974-1975/82/4

Notes on a class of tiling problems

Non-extensional equality

Multirelation et âge 1-extensifs

${\displaystyle {\aleph }_1}$ - Kategorische Theorien nicht-kommutativer Ringe

Relations on lines as primitive notions for Euclidean geometry

Pinning countable ordinals

Relativization of cylindric algebras