> term()
<term[0]>

> term(alpha = 2, beta = c(2, 2), "sigma")
<term[7]>
[1] alpha[1]  alpha[2]  beta[1,1] beta[2,1] beta[1,2] beta[2,2] sigma    

> term("alpha[1]", "sigma", "alpha[2]", "beta[1,1]", "beta[2,1]", "beta[1,2]",
+   "beta[2,2]")
<term[7]>
[1] alpha[1]  sigma     alpha[2]  beta[1,1] beta[2,1] beta[1,2] beta[2,2]

> new_term(c("with space", ""))
<term[2]>
[1] `with space` ``          

> term("r[")
Error in term_impl(args): All elements of term vector `string_args_term` must be valid.

> term("r  [ 1  ,2  ]")
<term[1]>
[1] r[1,2]