  The historic background of algorithmic processing with regard to etymology
and methodology is translated into terms of mathematical logic and Computer
Science. A formal logic structure is introduced by exemplaryquestions posed to
Fiqh-chapters to define alogic query language. As a foundation, ageneric
algorithm for deciding Fiqh-rulings is designed to enable and further leverage
rule of law (vs. rule by law) with full transparency and complete algorithmic
coverage of Islamic law eventually providing legal security, legal equality,
and full legal accountability.This is implemented by disentangling and
reinstating classic Fiqh-methodology (usul al-Fiqh) with the expressive power
of subsets of First Order Logic (FOL)sustainably substituting ad hoc reasoning
with falsifiable rational argumentation. The results are discussed in formal
terms of completeness, decidability and complexity of formal Fiqh-systems.
AnEntscheidungsproblem for formal Fiqh-Systems is formulated and validated.
