pointer to the multi symbol 168 if replace is chosen at step 141 the pointer is replaced using the method beginning with step 153 see fig9 b otherwise the pointer is erased at step 150 at step 153 if the symbol is the default symbol 160 the pointer is replaced with a pointer to the multi symbol 168 since the multi symbol appears like symbol 160 in its default state the multi symbol pointer 168 now preferably appears exactly like the default symbol pointer 160 though graphical or other indications that the entities are now a multi symbol can be displayed to the operator if the symbol is not the default a temporary symbol 182 see fig1 c is defined at step 143 which is made up of the entities of the alternate symbol second symbol 162 and a pointer to the multi symbol 168 the symbol pointer is then replaced with a pointer to the temporary symbol 182 the definitions of each of the member symbols are preserved and the multi symbol definition is linked to that of the member symbols such that if changes are made to the member symbols those changes will be reflected in the multi symbol the entities of each member symbol 180 can also be substituted in place of a pointer and referred to as a group of entities the symbol origins 174 176 and 178 of each alternate symbol 170 are preferably made to coincide with the symbol.