Portree used Portree's pier as a rest point. The town also began exporting fish at this time, which contributed greatly to the local economy. The town had the last manual telephone exchange in the UK, which closed in 1976. Portree shale is a geologic association in the vicinity of Portree, the existence of which is linked with potential petroleum occurrences of commercial importance. Portree Portree (; , ) is the largest town on Skye in the Inner Hebrides of Scotland. It is the location for the only secondary school on the island, Portree High School. Public transport services are limited to
Principal ideal principal ideals in formula_43 are of the form formula_44. Actually, every ideal formula_1 in formula_43 is principal, which can be shown in the following way. Suppose formula_47 where formula_48, then consider the surjective homomorphisms formula_49 Since formula_50 is finite, then for sufficiently large formula_51, formula_52 Thus, formula_53, which implies formula_1 is always finitely generated. Since the ideal generated by any integers formula_3 and formula_56, formula_57, is exactly formula_58, by induction on the number of generators, it follows that formula_1 is principal. However, all rings have principal ideals, namely, any ideal generated by exactly one element. For example, the ideal formula_60