Proofs of two Theorems concerning Sparse Spacetime Constraints
  In the SIGGRAPH 2014 paper [SvTSH14] an approach for animating deformable objects using sparse spacetime constraints is introduced. This report contains the proofs of two theorems presented in the paper. 
Christian Schulz, Christoph von Tycowicz, Hans-Peter Seidel and Klaus   Hildebrandt
cs.GR math.NA