NAT1254: Invalid size value for REDUCE/EXPAND/RESIZE: :1:.

Text	Invalid size value for REDUCE/EXPAND/RESIZE: ....
Expl.	A size value is specified with the REDUCE/EXPAND/RESIZE statement, in order to reallocate the memory for the given dynamic operand. The following conditions must be kept for the size value: 1. The size value must not be negative. 2. The size value must not exceed 1 gigabyte. The size value which caused the error is shown in the error message.
Actn.	Make sure the size value meets the conditions mentioned above.

NAT1255: Invalid value in ARRAY clause for REDUCE/EXPAND/RESIZE: :1:.

Text	Invalid value in ARRAY clause for REDUCE/EXPAND/RESIZE: ....
Expl.	The ARRAY clause of the REDUCE/EXPAND/RESIZE statement is provided in order to allow the number of occurrences of an X-array to be adjusted. The lower and upper bound values specified with the bound notation, or the number of occurrences specified with the occurrence notation, must meet the following conditions: 1. The fixed bound value must not be changed. 2. The number of occurrences must not be negative. 3. The number of occurrences must not exceed 1073741824. The value which caused the error is shown in the error message.
Actn.	Make sure the value meet the conditions above.

NAT1256: Value of system variable :1: is undefined.

Text	Value of system variable ... is undefined.
Expl.	A Natural statement references a system variable in order to get its value. The value of the system variable is currently undefined, due to the following reason: 1. The value of the system variable *UBOUND or *LBOUND is undefined if the corresponding X-array is not materialized (i.e. occurrences are not allocated). The system variable which caused the error is shown in the error message.
Actn.	Allocate occurrences of the corresponding X-array with the REDUCE/EXPAND/RESIZE statement before referencing *UBOUND or *LBOUND.

NAT1257: Access to a non-materialized X-array field not permitted.

Text	Access to a non-materialized X-array field not permitted.
Expl.	An X-array is an array field with an alterable number of occurrences. At runtime, an X-array is empty by default. It does not have any accessible occurrences, unless they were allocated before with an explicit EXPAND .. ARRAY statement.
Actn.	Allocate X-array occurrences with EXPAND .. ARRAY statement.

NAT1300: Negative exponent not allowed.

Text	Negative exponent not allowed.
Expl.	Natural performs an exponentiation via repetitive multiplication. Negative exponents are not permitted.
Actn.	Use only positive exponent values.