Marking of Differences

Lines in each descendant are marked according to their relationship to the corresponding lines in the common ancestor:

• If a line is identical in all three deltas, then no glyph appears.

• If a line is not in the ancestor but was added to one or both of the descendants, then a plus sign glyph (+) appears next to the line in the delta where the line was added.

• If a line is present in the ancestor but was removed from one or both of the descendants, then a minus sign (-) appears as a placeholder in the delta from which the line was removed.

• If a line is in the ancestor but has been changed in one or both of the descendants, then a vertical bar glyph (|) appears next to the line in the delta where the line was changed.

When Merging discovers a line that differs between either of the two deltas and the ancestor, it marks with glyphs the lines in the two deltas and also in the automatically merged file. Together, these marked lines are called a difference. While Merging is focusing on a difference, it highlights the glyphs.

The difference on which Merging is focusing at any given time is called the current difference. The difference that appears immediately later in the file is called the next difference; the difference that appears immediately earlier in the file is called the previous difference.