Work based on symbolic manipulations

\bibitem {rcc2}
X. S. Gao  \& S. C. Chou 
Solving Geometric Constraint Problems,
II. A Symbolic Approach and Decision of Rc-constructibility,

\bibitem{kondo} K. Kondo,
Algebraic method for manipulation of dimensional relationships
in geometric models, 
{\it Geometric Aided Design}, 24(3), 141-147, 1992.

\bibitem{buch} S A. Buchanan and A. de Pennington,
Constraint Definition System: A Computer-Algebra Based
Approach to Solving Geometric-Constraint Problems,
{\it Geometric Aided Design}, 25(12), 141-147, 1993.