A quasiminimal structure is a particular class of pregeometries (infinite finitary matroids). Quasiminimal excellent classes were defined by Zilber as useful axiomatic setup satisfying categoricity.
Literature
Introduced in
Boris Zilber, A categoricity theorem for quasi-minimal excellent classes, Logic and its applications, Contemporary Mathematics 380 (Amer. Math. Soc. 2005) 297–306.
In original treatments, among the axioms, excellence was hard/technical to prove. A breakthrough is a result that it is essentially automatic:
Martin Bays, Bradd Hart, Tapani Hyttinen, Meeri Kesälä, Jonathan Kirby, Quasiminimal structures and excellence, Bull. London Math. Soc. 46 (2014) 155–163 doi
Levon Haykazyan, Categoricity in quasiminimal pregeometry classes, J. Symb. Logic 81(1), 56–64 (2014) doiarXiv:1308.1892
Applications include
B. Zilber, Covers of the multiplicative group of an algebraically closed field of characteristic zero, J. London Math. Soc. (2) 74 (2006) 41–58
B. Zilber, Pseudo-exponentiation on algebraically closed fields of characteristic zero, Ann. Pure Appl. Logic 132 (2005) 67–95
Other
John T. Baldwin, Notes on quasiminimality and excellence, The Bulletin of Symbolic Logic 10:3 (2004) 334–366