Let's try this. It's BUGGERED.

src/cmd/eqn/tuning.c

@@ -0,0 +1,153 @@
+#include "e.h"
+
+/*
+
+This file contains parameter values for many of the
+tuning parameters in eqn.  Names are defined words.
+
+Strings are plugged in verbatim.
+Floats are usually in ems.
+
+*/
+
+/* In main.c: */
+
+double	BeforeSub = 1.2;	/* line space before a subscript */
+double	AfterSub  = 0.2;	/* line space after a subscript */
+
+/* diacrit.c: */
+
+double	Dvshift	= 0.25;		/* vertical shift for diacriticals on tall letters */
+double	Dhshift = 0.025;	/* horizontal shift for tall letters */
+double	Dh2shift = 0.05;	/* horizontal shift for small letters */
+double	Dheight	= 0.25;		/* increment to height for diacriticals */
+double	Barv	= 0.68;		/* vertical shift for bar */
+double	Barh	= 0.05;		/* 1/2 horizontal shrink for bar */
+double	Ubarv	= 0.1;		/* shift underbar up this much ems */
+double	Ubarh	= 0.05;		/* 1/2 horizontal shrink for underbar */
+
+/* Also:
+	Vec, Dyad, Hat, Tilde, Dot, Dotdot, Utilde */
+
+/* eqnbox.c: */
+
+char	*IRspace = "\\^";	/* space between italic & roman boxes */
+
+/* fat.c: */
+
+double	Fatshift = 0.05;	/* fattening shifts by Fatshift ems */
+
+/* funny.c: */
+
+int	Funnyps	= 5;		/* point size change (== 5 above) */
+double	Funnyht = 0.2;		/* height correction */
+double	Funnybase = 0.3;	/* base correction */
+
+/* integral.c: */
+
+int	Intps	= 4;		/* point size change for integral (== 4 above) */
+double	Intht	= 1.15;		/* ht of integral in ems */
+double	Intbase	= 0.3;		/* base in ems */
+double	Int1h	= 0.4;		/* lower limit left */
+double	Int1v	= 0.2;		/* lower limit down */
+double	Int2h	= 0.05;		/* upper limit right was 8 */
+double	Int2v	= 0.1;		/* upper limit up */
+
+/* matrix.c: */
+
+char	*Matspace = "\\ \\ ";	/* space between matrix columns */
+
+/* over.c: */
+
+double	Overgap	= 0.3;		/* gap between num and denom */
+double	Overwid	= 0.5;		/* extra width of box */
+double	Overline = 0.1;		/* extra length of fraction bar */
+
+/* paren.c* */
+
+double	Parenbase = 0.4;	/* shift of base for even count */
+double	Parenshift = 0.13;	/* how much to shift parens down in left ... */
+				/* ignored unless postscript */
+double	Parenheight = 0.3;	/* extra height above builtups */
+
+/* pile.c: */
+
+double	Pilegap	= 0.4;		/* gap between pile elems */
+double	Pilebase = 0.5;		/* shift base of even # of piled elems */
+
+/* shift.c: */
+
+double	Subbase	= 0.2;		/* subscript base belowe main base */
+double	Supshift = 0.4;		/* superscript .4 up main box */
+char	*Sub1space = "\\|";	/* italic sub roman space */
+char	*Sup1space = "\\|";	/* italic sup roman space */
+char	*Sub2space = "\\^";	/* space after subscripted thing */
+char	*SS1space = "\\^";	/* space before sub in x sub i sup j */
+char	*SS2space = "\\^";	/* space before sup */
+
+/* sqrt.c: */
+	/* sqrt is hard!  punt for now. */
+	/* part of the problem is that every typesetter does it differently */
+	/* and we have several typesetters to run. */
+
+/* text.c: */
+	/* ought to be done by a table */
+
+struct tune {
+	char	*name;
+	char	*cval;
+} tune[]	={
+  /* diacrit.c */
+	"vec_def",	"\\f1\\v'-.5m'\\s-3\\(->\\s0\\v'.5m'\\fP",	/* was \s-2 & .45m */
+	"dyad_def",	"\\f1\\v'-.5m'\\s-3\\z\\(<-\\|\\(->\\s0\\v'.5m'\\fP",
+	"hat_def",	"\\f1\\v'-.05m'\\s+1^\\s0\\v'.05m'\\fP",	/* was .1 */
+	"tilde_def",	"\\f1\\v'-.05m'\\s+1~\\s0\\v'.05m'\\fP",
+	"dot_def",	"\\f1\\v'-.67m'.\\v'.67m'\\fP",
+	"dotdot_def",	"\\f1\\v'-.67m'..\\v'.67m'\\fP",
+	"utilde_def",	"\\f1\\v'1.0m'\\s+2~\\s-2\\v'-1.0m'\\fP",
+  /* funny.c */
+	"sum_def",	"\\|\\v'.3m'\\s+5\\(*S\\s-5\\v'-.3m'\\|",
+	"union_def",	"\\|\\v'.3m'\\s+5\\(cu\\s-5\\v'-.3m'\\|",
+	"inter_def",	"\\|\\v'.3m'\\s+5\\(ca\\s-5\\v'-.3m'\\|",
+	"prod_def",	"\\|\\v'.3m'\\s+5\\(*P\\s-5\\v'-.3m'\\|",
+  /* integral.c */
+	"int_def",	"\\v'.1m'\\s+4\\(is\\s-4\\v'-.1m'",
+	0, 0
+};
+
+tbl	*ftunetbl[TBLSIZE];	/* user-defined names */
+
+char *ftunes[] ={	/* this table intentionally left small */
+	"Subbase",
+	"Supshift",
+	0
+};
+
+void init_tune(void)
+{
+	int i;
+
+	for (i = 0; tune[i].name != NULL; i++)
+		install(deftbl, tune[i].name, tune[i].cval, 0);
+	for (i = 0; ftunes[i] != NULL; i++)
+		install(ftunetbl, ftunes[i], (char *) 0, 0);
+}
+
+#define eq(s, t) (strcmp(s,t) == 0)
+
+void ftune(char *s, char *t)	/* brute force for now */
+{
+	double f = atof(t);
+	double *target;
+
+	while (*t == ' ' || *t == '\t')
+		t++;
+	if (eq(s, "Subbase"))
+		target = &Subbase;
+	else if (eq(s, "Supshift"))
+		target = &Supshift;
+	if (t[0] == '+' || t[0] == '-')
+		*target += f;
+	else
+		*target = f;
+}