# Cat - avram - a virtual machine code interpreter
avram - a virtual machine code interpreter

##### 2.7.14.1 Cat

The list concatenation operation has this representation in virtual code.

T28
  [[`cat`]] = `((nil,nil),(nil,nil))`

This function takes a pair of lists as an argument, an returns the list obtained by appending the right one to the left. The semantics of concatenation is what one would expect.

P35
  [[`cat`]] `(nil,`z`)` = z
P36
  [[`cat`]] `((`x`,`y`),`z`)` = `(`x`,`[[`cat`]] `(`y`,z))`