def p_EXPext(t):
' EXP : extract para FIELDS r_from timestamp cadena parc'
term = Extract(t[3], t[6])
t[0] = [term.getval(ent).valor, '']
def p_EXPext(t):
' EXP : extract para FIELDS r_from timestamp cadena parc'
listaBNF.append("EXP ::= extract para FIELDS from timestamp '" +
str(t[6]) + "' parc")
t[0] = Extract(t[3], t[6])
def p_EXPext(t):
' EXP : extract para FIELDS r_from timestamp cadena parc'
t[0] = Extract(t[3], t[6])