<%- if precondition.conjunction? -%>
<<%= precondition.conjunction_code_with_negation %>>
<%- precondition.preconditions.each do |child| -%>
<%= xml_for_precondition(child) %>
<%- end -%>
<%= precondition.conjunction_code_with_negation %>>
<%- else -%>
<%- end -%>