Error: Redefinition of the predefined type in file type_system13.dl at line 14
.type number = number
^---------------------
Error: Redefinition of the predefined type in file type_system13.dl at line 15
.type float <: unsigned
^-----------------------
Error: Redefinition of the predefined type in file type_system13.dl at line 16
.type symbol = [x: number, y: number]
^-------------------------------------
3 errors generated, evaluation aborted
