Second, the ''difference map'' (or the ''chordal transformation'') <math>\operatorname{D}G = (\operatorname{D}G_1, \operatorname{D}G_2) : \operatorname{E}U^\circ \to \operatorname{E}X^\circ</math> is defined in a component-wise fashion as the boolean sum of the initial proposition <math>G_j\!</math> and the ''enlarged'' or ''shifted'' proposition <math>\operatorname{E}G_j,</math> for <math>j = 1, 2,\!</math> in accord with following pair of equations:
<pre>
<pre>
−
Second, the "difference map" (or the "chordal transformation")
−
DG = <DG_1, DG_2> : EU% -> EX% is defined in a component-wise
−
fashion as the boolean sum of the initial proposition G_j and
−
the enlarged or the "shifted" proposition EG_j, for j = 1, 2,