Well, once again, I would refer you to the research conducted by the International Institute for Sustainable Development, where that's laid out in some detail.
According to a recommendation of the Green Budget Coalition, the Canadian exploration expense allows companies to deduct 100% of their exploration expenses from their income tax each year. In the coal sector, this includes intangible costs of mine development.
Then, presumably, there is the Canadian development expense, which allows companies to deduct 30% of their development expenses from their income tax each year. In the coal sector, this includes the cost of acquiring a mineral property or a right to explore.
So these issues are dealt with in a substantial amount of detail in the available research that's been done over the past little while.