On 3 March 20X1, Corvalis signs a contract with Hôtels Brésine to supply furniture for 400,000. On 10 March 20X1, it signs a contract with Brésine Services, a subsidiary of Hôtels Brésine, to install that furniture for 50,000. The correspondence shows that the installation price was set well below its usual level because the furniture price had been accepted. Installation and furniture are distinct goods and services (case datum). How does Corvalis analyse these contracts?