TY - JOUR T1 - The theory of classification part 2: The scratch-built typechecker JO - Journal of Object Technology PY - 2002/01/01 AU - Simons AJH ED - DO - DOI: 10.5381/jot.2002.1.2.c4 VL - 1 IS - 2 SP - 47 EP - 54 Y2 - 2025/11/29 ER -