Replace \bf in package desciption by \em as it sticks out with \bf

Algebraic_kernel_d/doc_tex/Algebraic_kernel_d/PkgDescription.tex

@@ -4,7 +4,7 @@
 Real solving of polynomials is a fundamental problem with a wide application range. 
 This package is targeted to provide black-box implementations of state-of-the-art 
 algorithms to determine, compare and approximate real roots of univariate polynomials
-and bivariate polynomial systems. Such a black-box is called an {\bf Algebraic Kernel}. 
+and bivariate polynomial systems. Such a black-box is called an {\em Algebraic Kernel}. 
 So far the package only provides models for the univariate kernel. Nevertheless, 
 it already defines concepts for the bivariate kernel, since this settles the interface
 for upcoming implementations.}