[exim] direct boolean values in AND failing

exim 4.66


assuming this:

set acl_c_pref_av_run     = 1
set acl_m_msg_av_allowed  = true

this:

    condition = ${if and {{$acl_c_pref_av_run} 
{$acl_m_msg_av_allowed}} {true}{false}}

is giving me the following error:

"${if and {{$acl_c_pref_av_run}{$acl_m_msg_av_allowed}} {true}
{false}}": condition name expected, but found "$acl_c_pref_av_r"
inside "and{...}" condition




even this:

    condition = ${if and {{1}{true}}}

gives me this:

failed to expand ACL string "${if and {{1}{true}}}": unknown
condition "1" inside "and{...}" condition



but this works:

    condition = ${if and { {eq{$acl_c_pref_av_run}{1}}{eq 
{$acl_m_msg_av_allowed}{1}} } {true}{false}}

and this works:

    condition = $acl_c_pref_av_run

does that make sense that I can't use a directly "boolean" values in
an AND test?

even this fails:

    condition = ${if and {{true}{true}}}

with this:

${if and {{true}{true}}}": unknown condition "true" inside "and{...}"
condition



strange but true