`graph.formula()`

was renamed to `graph_from_literal()`

to create a more
consistent API.

## Arguments

- ...
For

`graph_from_literal()`

the formulae giving the structure of the graph, see details below. For`from_literal()`

all arguments are passed to`graph_from_literal()`

.- simplify
Logical scalar, whether to call

`simplify()`

on the created graph. By default the graph is simplified, loop and multiple edges are removed.