instruction:
Given two noun phrases (arguments) and relationship between them, form a sentence that expresses theses arguments with the given relationship.
question:
Relationship: 'be head of', Argument/Subject 1: 'president', Argument/Subject 2: 'executive'
answer:
The service has been dubbed Derivatives Collateral Net and automatically aggregates and nets the overall collateral obligations of its participants , explains Art Certosimo , executive vice president and head of Broker-Dealer Services at the bank .

question:
Relationship: 'be locate on', Argument/Subject 1: 'post office', Argument/Subject 2: 'main street'
answer:
The Mt . Pleasant Post Office is located at 813 North Main Street at the corner of Main Street and Pickard Street , -772-0540 .

question:
Relationship: 'be state of', Argument/Subject 1: 'chiapa', Argument/Subject 2: 'mexico'
answer:
I gorged myself on some nachos and water while I thought about our great week in the state of Chiapas in southern Mexico .