Symbol cannot take arguments

Dear professor,

I’ ve been struggling for a while already when running the attached model file.
The error message is the following: “ERROR: Prueba1_Macro1.mod: line 53, cols 11-15: Symbol a cannot take arguments.”

error: Dynare: preprocessing failed
error: called from
dynare at line 282 column 5

Could you, please, help me to see whats wrong?
Prueba1_Macro1.mod (1.9 KB)

Your model block is missing the