IPFLang: A Domain-Specific Language for Multi-Currency Regulatory Fee Computation with Static Verification
Valer Bocan · Valentina E. Balas
Record
Abstract
Regulatory fee calculations involve complex, jurisdiction-specific rules typically implemented as ad-hoc code or spreadsheets, leading to errors and maintenance difficulties. No formal specification exists for encoding fee computation rules. This paper presents IPFLang, a domain- specific language addressing these software engineering challenges through novel language design and static verification. We develop a formal EBNF grammar with declarative fee computation blocks, a currency-aware type system supporting the 161 active ISO 4217 currencies, static analysis algorithms for completeness and monotonicity verification, and provenance tracking for auditability. The open-source reference implementation includes 118 production jurisdiction files covering PCT national/regional phase entry fees validated by a domain expert, a comprehensive test suite with 269 test methods achieving 100% pass rate, and sub-millisecond execution performance. The currency-aware type system prevents cross-currency arithmetic errors at compile time.
Notes
IPFLang is the language behind IPFees, which implements it against 118 jurisdictions.
Cite
@article{bocan2026ipflang,
author = {Bocan, Valer and Balas, Valentina E.},
title = {IPFLang: A Domain-Specific Language for Multi-Currency Regulatory Fee Computation with Static Verification},
journal = {IEEE Open Journal of the Computer Society},
year = {2026},
pages = {1--13},
publisher = {IEEE Computer Society},
issn = {2644-1268},
doi = {10.1109/OJCS.2026.3726037}
}