HeuristicLab supports tree-based (Koza-style) genetic programming. This classical form of genetic programming uses a tree-based representation of solution candidates. The data types and operators to work with tree-bsaed solution candidates are implemented in the plugin `HeuristicLab.Encodings.SymbolicExpressionTree`.

Supported operators (in 3.3.6):
 * Full tree creator
 * Grow tree creator
 * Ramped-half-half tree creator
 * Probabilistic tree creator (PTC)
 * Subtree crossover
 * Change node type manipulator (single point mutation, symbols)
 * Replace branch manipulator (removes a branch and replaces it with a randomly initialized branch)  
 * One-point shaker (single point mutation, only parameters)
 * Full-tree shaker (uniform mutation, only parameters)