DOC: Clarify relation between source locations through predicate_property and clause_propety.
DOC: Clarify relation between source locations through predicate_property
and clause_propety.

mndrix/swipl-devel,koryonik/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,jn7163/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel