Ittai Balaban Amir Pnueli Lenore D. Zuck Shape Analysis of Single-Parent Heaps. 91-105 2007 conf/vmcai/2007 VMCAI http://dx.doi.org/10.1007/978-3-540-69738-1_7 db/conf/vmcai/vmcai2007.html#BalabanPZ07