diff --git a/layouts/shortcodes/bergamot_widget.html b/layouts/shortcodes/bergamot_widget.html
index 59e791e..8f15aed 100644
--- a/layouts/shortcodes/bergamot_widget.html
+++ b/layouts/shortcodes/bergamot_widget.html
@@ -1,42 +1,75 @@
 <div id="{{ .Get "id" }}"></div>
 <script>
     const renderRules =
-        `LatexListNil @ latexlist(nil, nil) <-;
-         LatexListCons @ latexlist(cons(?x, ?xs), cons(?l_x, ?l_s)) <- latex(?x, ?l_x), latexlist(?xs, ?l_s);
+        `
+        PrecApp @ prec(app(?l, ?r), 100, left) <-;
+        PrecPlus @ prec(plus(?l, ?r), 80, either) <-;
+        PrecAbs @ prec(abs(?x, ?t, ?e), 0, right) <-;
+        PrecArr @ prec(tarr(?l, ?r), 0, right) <-;
 
-         IntercalateNil @ intercalate(?sep, nil, nil) <-;
-         IntercalateConsCons @ intercalate(?sep, cons(?x_1, cons(?x_2, ?xs)), cons(?x_1, cons(?sep, ?ys))) <- intercalate(?sep, cons(?x_2, ?xs), ?ys);
-         IntercalateConsNil @ intercalate(?sep, cons(?x, nil), cons(?x, nil)) <-;
+        SelectHead @ select(cons([?t, ?v], ?rest), ?default, ?v) <- ?t;
+        SelectTail @ select(cons([?t, ?v], ?rest), ?default, ?found) <- not(?t), select(?rest, ?default, ?found);
+        SelectEmpty @ select(nil, ?default, ?default) <-;
 
-         NonEmpty @ nonempty(cons(?x, ?xs)) <-;
+        ParenthAssocLeft @ parenthassoc(?a_i, left, right) <-;
+        ParenthAssocRight @ parenthassoc(?a_i, right, left) <-;
+        ParenthAssocNone @ parenthassoc(?a_i, none, ?pos) <-;
+        ParenthAssocNeq @ parenthassoc(?a_i, ?a_o, ?pos) <- not(symeq(?a_i, ?a_o));
 
-         LatexInt @ latex(?i, ?l) <- int(?i), tostring(?i, ?l);
-         LatexStr @ latex(?s, ?l) <- str(?s), escapestring(?s, ?l_1), latexifystring(?s, ?l_2), join(["\\\\texttt{\\"", ?l_2, "\\"}"], ?l);
-         LatexMeta @ latex(metavariable(?l), ?l) <-;
-         LatexIntLit @ latex(intlit(?i), ?l) <- latex(?i, ?l);
-         LatexStrLit @ latex(strlit(?s), ?l) <- latex(?s, ?l);
-         LatexVar @ latex(var(?s), ?l) <- latex(?s, ?l);
-         LatexPlus @ latex(plus(?e_1, ?e_2), ?l) <- latex(?e_1, ?l_1), latex(?e_2, ?l_2), join([?l_1, " + ", ?l_2], ?l);
-         LatexPair @ latex(pair(?e_1, ?e_2), ?l) <- latex(?e_1, ?l_1), latex(?e_2, ?l_2), join(["(", ?l_1, ",  ", ?l_2, ")"], ?l);
-         LatexAbs @ latex(abs(?x, ?t, ?e), ?l) <- latex(?e, ?l_e), latex(?t, ?l_t), latex(?x, ?l_x), join(["\\\\lambda ", ?l_x, " : ", ?l_t, " . ", ?l_e], ?l);
-         LatexApp @ latex(app(?e_1, ?e_2), ?l) <- latex(?e_1, ?l_1), latex(?e_2, ?l_2), join([?l_1, " \\\\enspace ", ?l_2], ?l);
+        Parenth @ parenth(?inner, ?outer, ?pos, ?strin, ?strout) <-
+            prec(?inner, ?p_i, ?a_i), prec(?outer, ?p_o, ?a_o),
+            join(["(", ?strin, ")"], ?strinparen),
+            select([ [less(?p_i, ?p_o), strinparen], [less(?p_o, ?p_i), ?strin], [ parenthassoc(?a_i, ?a_o, ?pos), ?strinparen ] ], ?strin, ?strout);
+        ParenthFallback @ parenth(?inner, ?outer, ?pos, ?strin, ?strin) <-;
 
-         LatexTInt @ latex(tint, "\\\\text{tint}") <-;
-         LatexTStr @ latex(tstr, "\\\\text{tstr}") <-;
-         LatexTArr @ latex(tarr(?t_1, ?t_2), ?l) <- latex(?t_1, ?l_1), latex(?t_2, ?l_2), join([?l_1, " \\\\to ", ?l_2], ?l);
-         LatexTPair @ latex(tpair(?t_1, ?t_2), ?l) <- latex(?t_1, ?l_1), latex(?t_2, ?l_2), join([?l_1, " \\\\times ", ?l_2], ?l);
+        LatexListNil @ latexlist(nil, nil) <-;
+        LatexListCons @ latexlist(cons(?x, ?xs), cons(?l_x, ?l_s)) <- latex(?x, ?l_x), latexlist(?xs, ?l_s);
 
-         LatexTypeEmpty @ latex(empty, "\\\\varnothing") <-;
-         LatexTypeExtend @ latex(extend(?a, ?b, ?c), ?l) <- latex(?a, ?l_a), latex(?b, ?l_b), latex(?c, ?l_c), join([?l_a, " , ", ?l_b, " : ", ?l_c], ?l);
-         LatexTypeInenv @ latex(inenv(?x, ?t, ?G), ?l) <-latex(?x, ?l_x), latex(?t, ?l_t), latex(?G, ?l_G), join([?l_x, " : ", ?l_t, " \\\\in ", ?l_G], ?l);
+        IntercalateNil @ intercalate(?sep, nil, nil) <-;
+        IntercalateConsCons @ intercalate(?sep, cons(?x_1, cons(?x_2, ?xs)), cons(?x_1, cons(?sep, ?ys))) <- intercalate(?sep, cons(?x_2, ?xs), ?ys);
+        IntercalateConsNil @ intercalate(?sep, cons(?x, nil), cons(?x, nil)) <-;
 
-         LatexTypeBin @ latex(type(?e, ?t), ?l) <- latex(?e, ?l_e), latex(?t, ?l_t), join([?l_e, " : ", ?l_t], ?l);
-         LatexTypeTer @ latex(type(?G, ?e, ?t), ?l) <- latex(?G, ?l_G), latex(?e, ?l_e), latex(?t, ?l_t), join([?l_G, " \\\\vdash ", ?l_e, " : ", ?l_t], ?l);
+        NonEmpty @ nonempty(cons(?x, ?xs)) <-;
 
-         LatexIsInt @ latex(int(?e), ?l) <- latex(?e, ?l_e), join([?l_e, " \\\\in \\\\mathbb{Z}"], ?l);
-         LatexIsStr @ latex(str(?e), ?l) <- latex(?e, ?l_e), join([?l_e, " \\\\in \\\\mathbb{S}"], ?l);
-         LatexSym @ latex(?s, ?l) <- sym(?s), tostring(?s, ?l_1), join(["\\\\text{", ?l_1,"}"], ?l);
-         LatexCall @ latex(?c, ?l) <- call(?c, ?n, ?ts), nonempty(?ts), latexlist(?ts, ?lts_1), intercalate(", ", ?lts_1, ?lts_2), join(?lts_2, ?lts_3), join(["\\\\text{", ?n, "}", "(", ?lts_3, ")"], ?l);
+        LatexInt @ latex(?i, ?l) <- int(?i), tostring(?i, ?l);
+        LatexStr @ latex(?s, ?l) <- str(?s), escapestring(?s, ?l_1), latexifystring(?s, ?l_2), join(["\\\\texttt{\\"", ?l_2, "\\"}"], ?l);
+        LatexMeta @ latex(metavariable(?l), ?l) <-;
+        LatexIntLit @ latex(intlit(?i), ?l) <- latex(?i, ?l);
+        LatexStrLit @ latex(strlit(?s), ?l) <- latex(?s, ?l);
+        LatexVar @ latex(var(?s), ?l) <- latex(?s, ?l);
+        LatexPlus @ latex(plus(?e_1, ?e_2), ?l) <-
+            latex(?e_1, ?l_1), latex(?e_2, ?l_2),
+            parenth(?e_1, plus(?e_1, ?e_2), left, ?l_1, ?lp_1),
+            parenth(?e_2, plus(?e_1, ?e_2), right, ?l_2, ?lp_2),
+            join([?lp_1, " + ", ?lp_2], ?l);
+        LatexPair @ latex(pair(?e_1, ?e_2), ?l) <- latex(?e_1, ?l_1), latex(?e_2, ?l_2), join(["(", ?l_1, ",  ", ?l_2, ")"], ?l);
+        LatexAbs @ latex(abs(?x, ?t, ?e), ?l) <- latex(?e, ?l_e), latex(?t, ?l_t), latex(?x, ?l_x), join(["\\\\lambda ", ?l_x, " : ", ?l_t, " . ", ?l_e], ?l);
+        LatexApp @ latex(app(?e_1, ?e_2), ?l) <-
+            latex(?e_1, ?l_1), latex(?e_2, ?l_2),
+            parenth(?e_1, app(?e_1, ?e_2), left, ?l_1, ?lp_1),
+            parenth(?e_2, app(?e_1, ?e_2), right, ?l_2, ?lp_2),
+            join([?lp_1, " \\\\enspace ", ?lp_2], ?l);
+
+        LatexTInt @ latex(tint, "\\\\text{tint}") <-;
+        LatexTStr @ latex(tstr, "\\\\text{tstr}") <-;
+        LatexTArr @ latex(tarr(?t_1, ?t_2), ?l) <-
+            latex(?t_1, ?l_1), latex(?t_2, ?l_2),
+            parenth(?t_1, tarr(?t_1, ?t_2), left, ?l_1, ?lp_1),
+            parenth(?t_2, tarr(?t_1, ?t_2), right, ?l_2, ?lp_2),
+            join([?lp_1, " \\\\to ", ?lp_2], ?l);
+        LatexTPair @ latex(tpair(?t_1, ?t_2), ?l) <- latex(?t_1, ?l_1), latex(?t_2, ?l_2), join(["(", ?l_1, ", ", ?l_2, ")"], ?l);
+
+        LatexTypeEmpty @ latex(empty, "\\\\varnothing") <-;
+        LatexTypeExtend @ latex(extend(?a, ?b, ?c), ?l) <- latex(?a, ?l_a), latex(?b, ?l_b), latex(?c, ?l_c), join([?l_a, " , ", ?l_b, " : ", ?l_c], ?l);
+        LatexTypeInenv @ latex(inenv(?x, ?t, ?G), ?l) <-latex(?x, ?l_x), latex(?t, ?l_t), latex(?G, ?l_G), join([?l_x, " : ", ?l_t, " \\\\in ", ?l_G], ?l);
+
+        LatexTypeBin @ latex(type(?e, ?t), ?l) <- latex(?e, ?l_e), latex(?t, ?l_t), join([?l_e, " : ", ?l_t], ?l);
+        LatexTypeTer @ latex(type(?G, ?e, ?t), ?l) <- latex(?G, ?l_G), latex(?e, ?l_e), latex(?t, ?l_t), join([?l_G, " \\\\vdash ", ?l_e, " : ", ?l_t], ?l);
+
+        LatexIsInt @ latex(int(?e), ?l) <- latex(?e, ?l_e), join([?l_e, " \\\\in \\\\mathbb{Z}"], ?l);
+        LatexIsStr @ latex(str(?e), ?l) <- latex(?e, ?l_e), join([?l_e, " \\\\in \\\\mathbb{S}"], ?l);
+        LatexSym @ latex(?s, ?l) <- sym(?s), tostring(?s, ?l_1), join(["\\\\text{", ?l_1,"}"], ?l);
+        LatexCall @ latex(?c, ?l) <- call(?c, ?n, ?ts), nonempty(?ts), latexlist(?ts, ?lts_1), intercalate(", ", ?lts_1, ?lts_2), join(?lts_2, ?lts_3), join(["\\\\text{", ?n, "}", "(", ?lts_3, ")"], ?l);
     `;
     const inputRules = `{{ .Get "prompt" }}`;
     var app = Elm.Main.init({