Roman \fIitalics\fP \fBboldface\fP
.x \(== "identically equal"
.x \(ca "cap (intersection)"
.x \(ib "improper subset"
.x \(pd "partial derivative"
.x \(pt "proportional to"
.x \(bs "bell system sign"
.x \(lt "left top (of big curly)"
.x \(lk "left center of big curly bracket"
.x \(rk "right center of big curly bracket"
.x \(lf "left floor (left bot of big sq bract)"
.x \(rf "right floor (rb of '')"
.x \(lc "left ceiling (lt of '')"
.x \(rc "right ceiling (rt of '')"