private void step4() {
        if (this.sb.length() > 1) {
            char ch = this.sb.charAt(this.sb.length() - 1);
            if (ch == 's') {
                char b = this.sb.charAt(this.sb.length() - 2);
                if ((b != 'a') && (b != 'i') && (b != 'o') && (b != 'u') && (b != 'è') && (b != 's')) {
                    this.sb.delete(this.sb.length() - 1, this.sb.length());
                    setStrings();
                }
            }
        }
        boolean found = deleteFromIfPrecededIn(this.R2, new String[]{"ion"}, this.RV, "s");
        if (!found) {
            found = deleteFromIfPrecededIn(this.R2, new String[]{"ion"}, this.RV, "t");
        }
        replaceFrom(this.RV, new String[]{"Ière", "ière", "Ier", "ier"}, "i");
        deleteFrom(this.RV, new String[]{"e"});
        deleteFromIfPrecededIn(this.RV, new String[]{"ë"}, this.R0, "gu");
    }