project to empty residual goals so that call_residue_vars/2 works
project to empty residual goals so that call_residue_vars/2 works

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