digraph G {
  # https://dreampuf.github.io/GraphvizOnline/
  homepage -> navigation;
  navigation -> start_new_derivation;
  google_signin [label="Google Sign-in"];
  google_signin -> navigation;
  specify_derivation_name_and_notes [label="specify derivation\n - derivation name\n - notes"];
  start_new_derivation -> google_signin;
  navigation -> show_all_derivations;
  show_all_derivations -> start_new_derivation;
  show_all_derivations -> review_derivation;
  start_new_derivation -> specify_derivation_name_and_notes;
  specify_derivation_name_and_notes -> select_inference_rule;
  review_derivation -> select_inference_rule [label="add another step"];
  provide_latex [label="provide {in,out,feed} latex\n - step note"];
  select_inference_rule -> provide_latex;
  provide_latex -> step_review;
  step_review -> select_inference_rule [label="accept; add another step"];
  step_review -> review_derivation [label="accept; review derivation"];
  step_review -> modify_step [label="modify step"];
  modify_step -> step_review [label="edit expression latex"];
  modify_step -> review_derivation [label="delete step"];
  review_derivation -> derivation_html;
  review_derivation -> derivation_tex;
  review_derivation -> derivation_pdf;
}