anchor.diff:             :v-true-type
   
              ;;types
  +           :add-type-shadow
  +           :un-shadow
              :v-t-type
              :v-type
              :v-stemcell
  
positive.code:            ;;definitions
             :v-defstruct
             :v-defun
             
             ;;compiler
             :varjo->glsl
  
  
negative.code:            :find-mutual-cast-type
  
             ;;environment
             :environment
             :make-varjo-environment
  
             ;;type functions
  