case ir.OLITERAL, ir.ONIL, ir.ONAME, ir.OLINKSYMOFFSET, ir.OMETHEXPR,
			ir.OAND, ir.OANDNOT, ir.OLSH, ir.OOR, ir.ORSH, ir.OXOR, ir.OCOMPLEX, ir.OMAKEFACE,
			ir.OADDR, ir.OBITNOT, ir.ONOT, ir.OPLUS,
			ir.OCAP, ir.OIMAG, ir.OLEN, ir.OREAL,
			ir.OCONVNOP, ir.ODOT,
			ir.OCFUNC, ir.OIDATA, ir.OITAB, ir.OSPTR,
			ir.OBYTES2STRTMP, ir.OGETG, ir.OGETCALLERPC, ir.OGETCALLERSP, ir.OSLICEHEADER, ir.OSTRINGHEADER:

	"⊖":                          "\u2296",
	"𝕠":                            "\U0001d560",
	"⦷":                            "\u29b7",
	"⦹":                           "\u29b9",
	"⊕":                           "\u2295",
	"∨":                              "\u2228",
	"↻":                           "\u21bb",
	"⩝":                             "\u2a5d",

		ir.OCONVNOP,
		ir.ODIV,
		ir.ODOT,
		ir.ODOTTYPE,
		ir.OLITERAL,
		ir.OLSH,
		ir.OMOD,
		ir.OMUL,
		ir.ONEG,
		ir.ONIL,
		ir.OOR,
		ir.OOROR,
		ir.OPAREN,
		ir.OPLUS,
		ir.ORSH,
		ir.OSUB,
		ir.OXOR:
		return false
	}

	// Be conservative.
	return true
}

// expand append(l1, l2...) to
//
//	init {
//	  s := l1

        entities.put("sub", "\u2282");
        entities.put("sup", "\u2283");
        entities.put("nsub", "\u2284");
        entities.put("sube", "\u2286");
        entities.put("supe", "\u2287");
        entities.put("oplus", "\u2295");
        entities.put("otimes", "\u2297");
        entities.put("perp", "\u22a5");
        entities.put("sdot", "\u22c5");
        entities.put("lceil", "\u2308");
        entities.put("rceil", "\u2309");

		ir.OLE,
		ir.OGT,
		ir.OGE,
		ir.OKEY,
		ir.OSTRUCTKEY,
		ir.OLEN,
		ir.OMUL,
		ir.OLSH,
		ir.ORSH,
		ir.OAND,
		ir.OANDNOT,
		ir.ONEW,
		ir.ONOT,
		ir.OBITNOT,
		ir.OPLUS,
		ir.ONEG,
		ir.OOROR,
		ir.OPAREN,
		ir.ORUNESTR,
		ir.OREAL,
		ir.OIMAG,
		ir.OCOMPLEX:
		return false

	// Only possible side effect is division by zero.
	case ir.ODIV, ir.OMOD:

		n := n.(*ir.SelectorExpr)
		return n.FuncName()

	case ir.OMIN, ir.OMAX:
		n := n.(*ir.CallExpr)
		return walkMinMax(n, init)

	case ir.ONOT, ir.ONEG, ir.OPLUS, ir.OBITNOT, ir.OREAL, ir.OIMAG, ir.OSPTR, ir.OITAB, ir.OIDATA:
		n := n.(*ir.UnaryExpr)
		n.X = walkExpr(n.X, init)
		return n

	case ir.ODOTMETH, ir.ODOTINTER:
		n := n.(*ir.SelectorExpr)

			} else {
				add.List.Append(r)
			}
			add.SetType(t)
			return add
		}
		n.X, n.Y = l, r
		n.SetType(t)
		return n

	case ir.OBITNOT, ir.ONEG, ir.ONOT, ir.OPLUS:
		n := n.(*ir.UnaryExpr)
		return tcUnaryArith(n)

	// exprs
	case ir.OCOMPLIT:
		return tcCompLit(n.(*ir.CompLitExpr))

	case ir.OXDOT, ir.ODOT:
		n := n.(*ir.SelectorExpr)

	"equiv":    "\u2261",
	"le":       "\u2264",
	"ge":       "\u2265",
	"sub":      "\u2282",
	"sup":      "\u2283",
	"nsub":     "\u2284",
	"sube":     "\u2286",
	"supe":     "\u2287",
	"oplus":    "\u2295",
	"otimes":   "\u2297",
	"perp":     "\u22A5",
	"sdot":     "\u22C5",
	"lceil":    "\u2308",
	"rceil":    "\u2309",
	"lfloor":   "\u230A",
	"rfloor":   "\u230B",
	"lang":     "\u2329",

            classpath = classpath.plus(moduleRegistry.getModule("gradle-language-groovy").getImplementationClasspath());
            classpath = classpath.plus(moduleRegistry.getExternalModule("groovy").getClasspath());
            classpath = classpath.plus(moduleRegistry.getExternalModule("groovy-json").getClasspath());
            classpath = classpath.plus(moduleRegistry.getExternalModule("groovy-xml").getClasspath());

        return PersistentList.<T>of().plus(first);
    }

    @SafeVarargs
    public static <T> PersistentList<T> of(T first, T second, T... rest) {
        PersistentList<T> result = of();
        for (int i = rest.length - 1; i >= 0; i--) {
            result = result.plus(rest[i]);
        }
        return result.plus(second).plus(first);
    }

    @Override