Introduction

digraph Flatland { a -> b -> c -> g; a [shape=polygon,sides=4] b [shape=polygon,sides=5] c [shape=polygon,sides=6] g [peripheries=3,color=yellow]; s [shape=invtriangle,peripheries=1,color=red,style=filled]; w [shape=triangle,peripheries=1,color=blue,style=filled]; }