The court discusses the burden of proof of the grounds for refusing enforcement under the Convention.
Burden of proof on respondent
507
Invalidity of the arbitration agreement: The court discusses other cases of invalidity of the arbitration agreement, including that there was no agreement at all or that the party was not a signatory thereto, that the incorrect arbitral institution was chosen, etc.
Miscellaneous cases regarding the arbitration agreement
513
Ground d: Irregularity in the composition of the arbitral tribunal or arbitral procedure