 
            
            
            
            
                13 Mar
                
                    2018
                
            
            
                13 Mar
                
                '18
                
            
            
            
        
    
                11:45 p.m.
            
        I just noted that ST is an instance of MonadFail, with fail throwing an error. This seems utterly contrary to the purpose of MonadFail! Can we please remove this instance? David Feuer