Why do I get a (3,2) expected statement error here?

[MAURICE ELLIS]

Why do I get a (3,2) expected statment error here?

'CATHY:
'  Initialise:
 LET Dictionary=1000
 Dim Context$(Dictionary)
 Dim Alternatives$(Dictionary)
 Let EmptyRow = 0
 Let EndOfResponseCharacter$ = CHR$(180)
 Let ContextLength = 6 
 Let CurrentContext$ = STRING$(ContextLength, EndOfResponseCharacter$)
 Let DictionaryFile$ = "CATHY.MEM"
 RANDOMIZE TIMER
    RETURN