"Composing Contracts" launched much of the use of FP in the finance industry. It was specifically cited in Credit Suisse's use for modelling contracts, for exam

"Composing Contracts" launched much of the use of FP in the finance industry. It was specifically cited in Credit Suisse's use for modelling contracts, for example. That said, any required language should be fully formally specified -- what's the semantics of a Python contract? Implementation defined? A testsuite?