0

In BEAF notation, I have deduced that
$$f(a,0,0,0,0)\approx\{a,2,1,2\}$$
$$f(a,b,0,0,0)\approx\{a,b+1,2,2\}$$
$$f(a,b,1,0,0)\approx\underbrace{\{a,\{a,\{a,\{a,\{}_{\{a,b+1,2,2\}}\dots\}+1,2,2\}+1,2,2\}+1,2,2\}+1,2,2\}$$
$$f(a,b,c,0,0)\approx c\left\lbrace\tiny\underbrace{\{a,\{a,\{a,\{a,\{a,\...