| − | Intuitively, we want to map this ('''B'''<sup>2</sup>)<sup>''n''</sup> onto''D''<sup>''n''</sup> by mapping each component'''B'''<sup>2</sup> onto a copy of'''D'''.  But inour current situation "'''D'''" is just a namewe give, or anaccidental qualitywe attribute,to coefficient values in'''B''' when they are attached to features ind<font face="lucida calligraphy">X</font>. | + | Intuitively, we want to map this <math>(\mathbb{B}^2)^n</math> onto <math>\mathbb{D}^n</math> by mapping each component <math>\mathbb{B}^2</math> onto a copy of <math>\mathbb{D}.</math>  But in the presenting context "<math>\mathbb{D}</math>" is just a name associated with, or an incidental quality attributed to, coefficient values in <math>\mathbb{B}</math> when they are attached to features in <math>\operatorname{d}\mathcal{X}.</math> | 
| − | Therefore, defined''x''<sub>''i''</sub> :''X''<sup>2</sup>→ '''B''' such that:
 | + | Taking these inetntions into account, define <math>\operatorname{d}x_i : X^2 \to \mathbb{B}</math> in the following manner: |