Problema utilizando o Extract, Interbase 6.0

SELECT
  F.CODFUNCIONARIO AS CODIGO  ,  F.NOME           AS NOME    ,
  F.DESCRCBO       AS FUNCAO  ,  F.ADMISSAO       AS ADMISSAO,
  F.SALARIO        AS SALARIO ,
  ( F.ADMISSAO + F.TEMPOEXPERIENCIA ) AS VENCIMENTO,
  ( F.ADMISSAO + F.TEMPOEXPERIENCIA + F.PRORROGACAO ) AS PRORROGACAO
FROM
  FUNCIONARIOS F
WHERE  F.TEMPOEXPERIENCIA IS NOT NULL
AND F.PRORROGACAO IS NOT NULL
AND F.CODEMPRESA = 1  AND F.CODFUNCIONARIO = ´010´
AND EXTRACT( MONTH FROM ( F.ADMISSAO + F.TEMPOEXPERIENCIA )  )= 01
AND EXTRACT( YEAR FROM  ( F.ADMISSAO + F.TEMPOEXPERIENCIA + F.PRORROGACAO ) )  = 2007
OR EXTRACT( MONTH FROM ( F.ADMISSAO  + F.TEMPOEXPERIENCIA   + F.PRORROGACAO ) ) = 01
AND EXTRACT( YEAR FROM ( F.ADMISSAO + ( F.TEMPOEXPERIENCIA + F.PRORROGACAO ) ) )  = 2007
ORDER BY FUNCIONARIOS.CODFUNCIONARIO, FUNCIONARIOS.NOME, FUNCIONARIOS.CODEMPRESA