R.I. Gen. Laws § 28-9-2: Enforceability of agreement to arbitrate existing or prior controversy.

An agreement in writing between an employer and an association of employees, a labor union, trade union, or craft union, or between an association of employers and an association of employees, labor unions, trade unions, or craft unions, to submit to arbitration any controversy existing between them prior to and at the time of the agreement shall be valid, irrevocable, and enforceable, except upon any grounds that exist in law or in equity for the revocation of the contract.