1. The growth steps are expressed by: $\text{P}_{x} + \text{P}_{y}\rightarrow \text{P}_{x + y}\hspace{35pt} \{x\}\in \{1,2, \dots \infty\}; \{y\}\in \{1,2, \dots \infty \}$ where $$\text{P}_{x}$$ and $$\text{P}_{y}$$ denote chains of degrees of @P04740@ $$x$$ and $$y$$, respectively.