premise: It rested its decision solely on 7 , which reads in pertinent part : `` [ N ] o corporation engaged in commerce shall acquire , directly or indirectly , the whole or any part of the stock or other share capital of another corporation engaged also in commerce , where the effect of such acquisition may be to substantially lessen competition between the corporation whose stock is so acquired and the corporation making the acquisition , or to restrain such commerce in any section or community , or tend to create a <mask> of any line of commerce .
hypothesis: the proper context for <mask> here should be (economics) a market in which there are many buyers but only one seller