In other words, M cannot correctly distinguish between a string of equal number of 'a's and 'b's and a string with 'a's and 'b's.

For example, the following correctly distinguish between use and mention:

They found that from the age of three years, children were able to distinguish correctly between intended actions and mistakes (Shultz, 1980).

Scientists have had difficult determining the characteristics of Lambda Boötis-type stars because of the difficulty in correctly distinguishing them from Delta Scuti-type stars, among others.

Becker failed in the end to correctly distinguish classical and intuitionistic negation, but he made a start.

Brain fingerprinting correctly distinguished the FBI agents from the non-agents.

However, the grammar must be able to correctly distinguish word hypotheses or the number of paths will grow exponentially.

All three classifiers correctly distinguished between A549 and U118 cell cultures.

Analysis of the spectral content of the sound, its envelope, and other heuristics are also commonly used methods to distinguish and correctly classify impulsive sounds as gunfire.

Hence the difficulty in correctly distinguishing between the Community aspect and the intergovernmental cooperation aspect, a distinction that is necessary if we are to target them properly.