Æliens

1

• abstraction -- control and data
• abstract data types -- values in a semantic domain
• types as constraints -- mathematical models

2

• signature -- producers and observers
• generator universe -- equivalence classes
• initial model -- no junk, no confusion
• objects -- multiple world semantics

3

• data abstraction -- generators/observers matrix
• modules -- operation-oriented
• objects -- data-oriented

4

• types -- syntactically, semantically, pragmatically
• compatible modifications -- type, signature, class