(a) “Arbitration agreement” is an agreement by the parties to submit to arbitration all or certain disputes that have arisen or that may arise between them in respect of a defined legal relationship, whether contractual or not. An arbitration agreement may be in the form of an arbitration clause in a contract or in the form of a separate agreement.
     (b) The arbitration agreement shall be in writing. An agreement is in writing if it is contained in a document signed by the parties or in an exchange of letters, telex, telegrams, or other means of telecommunication that provides a record of the agreement or in an exchange of statements of claim and defense in which the existence of an agreement is alleged by one party and not denied by another. The reference in a contract to a document containing an arbitration clause constitutes an arbitration agreement, provided that the contract is in writing and the reference is such as to make that clause part of the contract.