negation - Excluding certain property values in inline query -

i use 3 values (=pages) a, b, c property is of type.

some pages have 1 value is of type, pages have 3 values.

i want #ask pages of type a without being of type b , c.

i tried following inline query:

{{#ask: [[is of type::a]] [[is of type::!b]] [[is of type::!c]]}} 

but doesn’t work intended: lists pages of type a, including of type b/c in addition.

semantic mediawiki isn't @ subtractive queries. query translates in english to:

find me every page has of these: -an instance of property "is of type" equal -an instance of property "is of type" not equal b -an instance of property "is of type" not equal c

now here's "gotcha": suppose have page "is of type" a, b, , c. -it of type a. -it of type isn't b, namely , c. -it of type isn't c, namely , b.

it fits of conditions, , goes in result.

i run these types of problems often. wiki has several templates subtracting query results.