# HBO0052I The expression is too complex.

## Explanation

An expression contains a nested structure of a depth that the System Data Engine cannot process. The System Data Engine stops processing the current statement and continues with the next.

There are two kinds of nested structures: the parentheses and the constructs involving alternatives (the VALUE function and case expressions). The nesting depth of parentheses at a given point is equal to the number of pairs of parentheses enclosing that point. The parentheses include those that are a part of function calls with more than one argument and the implicit parentheses inserted to enforce the precedence of operations. For example, A*B+C*D has these implicit parentheses: (A*B)+(C*D). The nesting depth of alternative structures at a given point is the number of nested VALUE calls and case expressions containing that point, plus the number of preceding arguments within each VALUE call, plus the number of preceding THEN clauses within each case expression. This message indicates that one or both of these nesting depths exceed the maximum that can be handled by the System Data Engine.

## Response

If possible, define parts of the expression separately by using the LET clause. Otherwise, try to restructure the expression to reduce the nesting depth. For example, change the sequence of operators, and specify complex cases first, in case expressions.