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4.3.1. Space-resolution Rules

3. Alternatively if all of the remaining space-specifiers in S' are non-forcing, then the resolved spacespecifier is defined in terms of those non-suppressed space-specifiers whose precedence is numerically highest, and among these those whose optimum value is the greatest. All other space-specifiers are suppressed. If there is only one of these then its value is taken as its resolved value. Otherwise, follow these rules when there are two or more space-specifiers all of the same highest precedence and the same (largest) optimum: The resolved space-specifier of the last space-specifier in the sequence is derived from these spaces by taking their common optimum value as its optimum.
The greatest of their minimum values is its minimum. The least of their maximum values is its maximum. All other space-specifiers are suppressed.