In T 1814/11 the problem to be solved was to provide an alternative synergistically active fungicidal composition based on prothioconazole. The board concluded that synergistic effects were not foreseeable, i.e. even if a combination of two specific compositions had a synergistic effect as in document 1, such synergy could not necessarily be expected if the structure of one of the two compositions were modified. Synergy was not in principle foreseeable and therefore could not be attributed to a specific mechanism of action and/or structure. The board dismissed the respondent's suggestion of trial-and-error experimentation as inappropriate in this case.