Function logic_expr_to_proof_expr_defeasible 

pub fn logic_expr_to_proof_expr_defeasible<'a>(
    expr: &LogicExpr<'a>,
    interner: &Interner,
    defaults: &mut Vec<DefaultRule>,
) -> ProofExpr

Convert with DEFEASIBLE semantics: a generic GEN x(R(x) → N(x)) becomes the abnormality-guarded ∀x((R(x) ∧ ¬ab_k(x)) → N(x)), and an implicature is asserted under its own guard (assertion ∧ (¬ab_k → implicature)). The circumscription itself — minimizing each ab_k — happens in the defeasible reasoner; this conversion only preserves what the strict export (Generic → ∀, implicature dropped) erases.