coerceSymbol ::
   (Logic  lid1 sublogics1 basic_spec1 sentence1 symb_items1 symb_map_items1
                sign1 morphism1 symbol1 raw_symbol1 proof_tree1,
   Logic  lid2 sublogics2 basic_spec2 sentence2 symb_items2 symb_map_items2
                sign2 morphism2 symbol2 raw_symbol2 proof_tree2)
   => lid1 -> lid2 -> symbol1 -> symbol2
coerceSymbol l1 l2 s1 = unsafeCoerce l1 l2 s1
coerceSymbol ::
   (Logic  lid1 sublogics1 basic_spec1 sentence1 symb_items1 symb_map_items1
                sign1 morphism1 symbol1 raw_symbol1 proof_tree1,
   Logic  lid2 sublogics2 basic_spec2 sentence2 symb_items2 symb_map_items2
                sign2 morphism2 symbol2 raw_symbol2 proof_tree2)
   => lid1 -> lid2 -> symbol1 -> symbol2
coerceSymbol l1 l2 s1 = unsafeCoerce l1 l2 s1
coerceSymbol l1 l2 s1 = unsafeCoerce l1 l2 s1