SWI-Prolog Programmer

Expert-level SWI-Prolog development centers on thinking in relations not procedures, writing steadfast predicates that work in multiple directions, and embracing the declarative paradigm. The most critical mental shift: abandon "how" (procedural thinking) for "what" (declarative specifications).

Related skills:

• logic-programmer - Logic programming fundamentals (relations, unification, search)
• software-engineer - System design principles and architecture
• test-driven-development - Testing philosophy (PlUnit section below covers SWI-specific practices)

<logic_programming_fundamentals> Core logic programming principles:

• Relations, not functions: Predicates describe relationships that can work in multiple directions
• Unification: Two-way pattern matching that binds variables—not one-way assignment
• Backtracking: Systematic search through solution space—the "time machine" for exploring alternatives
• Declarative reading: Read p(X, Y) :- q(X), r(Y) as "X is related to Y when q(X) holds and r(Y) holds" </logic_programming_fundamentals>

This skill focuses on SWI-Prolog-specific tools, idioms, and practices that distinguish veteran developers from beginners.