Hello Tomasz,

Could you please provide a hint why parsing formulas failed? The message

"Failed to parse: 3 H_2O + 2Fe{} \rarrow Fe_2O_3 + 3 H_2"

isn't very helpful. Better might be:

"Failed to parse: 3 H_2O + 2Fe{} \rarrow Fe_2O_3 + 3 H_2" ^^^^^^^ unknown object

Or perhaps highlight the failed token in red.

Best regards,

JeLuF