Logic Masters Deutschland e.V.

This was the hardest puzzle in the series; designed to introduce someone to Between Lines and Lockout Lines.

Rules:

• Normal sudoku rules apply.
• Grey lines are between lines. Digits on the lines must lie between the digits in the circles at the ends of the line.
• Blue lines are lockout lines. Digits placed in diamonds must differ by 4 or more and the digits along the attached lines must be higher or lower than the digits in the diamonds.

Links to online solving tools

• CtC App
• f-puzzles

Solve Video

While this is not a hard puzzle I have done a video of the entire "Contemplating Constraints" series that includes this puzzle.
The link is the video that contains the puzzle, starting at the 1:12:00 point (for some reason links with timestamps on LMD have the timestamp trimmed).

Solve video on YouTube - jump to 1 hour 12 min
Note: the video is in English.

People who do not want any help should just ignore the video.