# Summary

The grammar of Algol 68 is expressed in terms of a few primitive concepts: value, mode, context, coercion and phrase. A phrase is either a declaration or a unit. There are 5 contexts, 7 coercions, 22 different kinds of unit and potentially an infinite number of values and modes. The coercions available in each context have been described. Balancing is the means by which alternatives in conditional, case and conformity clauses and the two sides of an identity relation are coerced to a common mode, possibly making coercions available which would not normally be so in the context of the construct concerned.

No exercises are provided at this point.