Definition · finite construction

FPRD-RE-D01

Finite partial-derivative carrier

Exact statement

For a regular expression BB, let QBQ_B be a finite Antimirov partial-derivative carrier containing BB and closed under one-letter partial derivatives.

StatusClassical construction stated for the quotient proof
External reviewNo documented external or specialist review of this FPRD result is recorded.

Context

The finite carrier supplies the states over which a quotienting expression can be interpreted as a relation.

Definitions

  • For a word uu, ∂u(P)\partial_u(P) denotes the finite set of Antimirov partial derivatives reached from PP.

Hypotheses and scope

  • The alphabet is finite and regular expressions use the ordinary 0, 1, letter, union, concatenation, and star constructors.

Proof or evidence

Finiteness is the standard partial-derivative theorem; the quotient construction uses only states reachable from B.

Verification notes

The FPRD proof checked closure under letters and used the carrier only as a finite auxiliary object, not as an additional language operation.

Limitations

  • This record invokes the classical finiteness theorem rather than reproving it from first principles.

Open work

Make the carrier construction fully explicit in a mechanized implementation.