| http://www.w3.org/ns/prov#value | - f the formula wherein X is selected from the group consisting of oxygen atom, sulfur atom, alkyl imino group (R9???N???, wherein R9 is an alkyl group with from about 1 to about 10 carbons), and aryl imino group (Ar???N???, wherein Ar is a phenyl group); R1 and R2 are individually selected from the group consisting of: alkyl of from 1 to 20 carbon atoms, aryl, and carbocyclic systems; R3 and R4 are
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