model SAP1 - NETDEMANDQTY Key Figure Question

In the input table for the l script,  there is a reference to SM1PRDNUM and SM1LOCNUM.   These two are defined as Int32.   However there are no attributes or master data types called SM1PRDNUM or SM1LOCNUM.   What do SM1PRDNUM and SM1LOCNUM refer to in the l script?

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