fundemental

Fundemental is likely misspelled.

Fundemental has no English definition.

As an adjective integral

is constituting a whole together with other parts or factors; not omittable or removable.

As a noun integral

is a number, the limit of the sums computed in a process in which the domain of a function is divided into small subsets and a possibly nominal value of the function on each subset is multiplied by the measure of that subset, all these products then being summed.

As an adjective substantial is

having to substance; actually existing; real; as, substantial life.

As a noun substantial is

anything having substance; an essential part.