https://github.com/SuperJMN/Plotty/blob/e760f809f5a9c5bd648609c074939761b51a31b4/Plotty.Model/BooleanOperator.cs#L15 Change OR operator symbol from '**&&**' to '**||**'.
Plotty/Plotty.Model/BooleanOperator.cs
Line 15 in e760f80
Change OR operator symbol from '&&' to '||'.