ABSTRACT. Pre-mappable (PreM ) extrema constraints in recursive Datalog programs enable concise declarative formulations for classical algorithms (Zaniolo et al. 2017). The programs expressing these algorithms have formal non- monotonic semantics with efficient and scalable support on multiple platforms (Shkapsky et al. 2016) (Yang et al. 2017). However proving PreM for different programs can be challenging for programmers; thus, in this paper, we introduce simple templates that allow users to verify with ease that their programs have the PreM property along with the rigorous semantics and the efficient and scalable implementation associated with it. We thus obtain simple declarative formulation for classical algorithms in two equivalent versions: one with perfect model semantics and the other with stable model semantics.