] * sizeof(token_type));
			*np = n_lhs[i];
		}
		list_proc(equation, *np, false);
		fprintf(gfp, "\n");
		return cp2;
	}
	return parse_section(equation, np, cp);
}

/*
 * Get an expression from the user.
 * The prompt must be previously copied into the global prompt_str[].
 *
 * Return true if successful.
 */
int
get_expr(equation, np)
token_type	*equation;	/* where the parsed expression is stored (equation side) */
int		*np;		/* pointer to the returned parsed expression length */
{
	char	buf[DEFAULT_N_TOKENS];
	char	*cp;

	for (;;) {
		if ((cp = get_string(buf, sizeof(buf))) == NULL) {
			return false;
		}
		if (!case_sensitive_flag) {
			str_tolower(cp);
		}
		cp = parse_expr(equation, np, cp);
		if (cp && !extra_characters(cp)) {
			break;
		}
	}
	return(*np > 0);
}

/*
 * Prompt for a variable name from the user.
 *
 * Return true if successful.
 */
int
prompt_var(vp)
long	*vp;	/* pointer to the returned variable */
{
	char	buf[MAX_CMD_LEN];
	char	*cp;

	for (;;) {
		my_strlcpy(prompt_str, _("Enter variable: "), sizeof(prompt_str));
		if ((cp = get_string(buf, sizeof(buf))) == NULL) {
			return false;
		}
		if (*cp == '\0') {
			return false;
		}
		cp = parse_var2(vp, cp);
		if (cp == NULL || extra_characters(cp)) {
			continue;
		}
		return true;
	}
}

/*
 * Return true and display a message if equation "i" is undefined.
 */
int
not_defined(i)
int	i;	/* equation space number */
{
	if (i < 0 || i >= n_equations) {
		error(_("Invalid equation number."));
		return true;
	}
	if (n_lhs[i] <= 0) {
		error(_("Equation space is empty."));
		return true;
	}
	return false;
}

/*
 * Verify that a current equation or expression is loaded.
 *
 * Return true and display a message if current equation