Logical Operation

A Logical Operation is a per-sample operation applied between the fragment's color values and color values in the corresponding sample in the framebuffer. They are performed independently for the RGBA components of the colors, and they only work for framebuffer attachments that are integers (normalized or not). And even then, they do not work for SRGB Image Formats if GL_FRAMEBUFFER_SRGB is active.

Enabling logical operations automatically turns off Blending.