Prove:

        (fg)    ,

under the assumptions:

        (d+)    ,

        (c+)    .

For proving (fg) we take all variables arbitrary but fixed and prove:

        (1)    .

Using (d+) , the goal (1) is transformed into:

        (2)    .

Formula (2) is proved because it is an instance of (c+).

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Converted by Mathematica      December 20, 2004