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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def _convert_verbal_form( analysis ):
    ''' Converts ordinary verbal categories of the input analysis. 
        Performs one-to-one conversions. '''
    assert FORM in analysis, '(!) The input analysis does not contain "'+FORM+'" key.'
    for form, replacement in _verb_conversion_rules:
        # Exact match
        if analysis[FORM] == form:
           assert analysis[POSTAG] == 'V', \
               '(!) Expected analysis of verb, but got analysis of "'+str(analysis[POSTAG])+'" instead.'
           analysis[FORM] = replacement
        # Inclusion :   the case of some_prefix+' '+form ;
        elif analysis[FORM].endswith(' '+form):
           parts  = analysis[FORM].split()
           prefix = ' '.join( parts[:len(parts)-1] )
           analysis[FORM] = prefix+' '+replacement
    return analysis