Casement/leaf arrangement having a casement/leaf of a window or a door, and method for frontal installation of a fitting part in casement/leaf

A casement/leaf arrangement having a casement/leaf of a window or door, with a frame profile of the casement/leaf, said frame profile having a C-shaped casement/leaf groove in a rebate, and with at least one fitting part insertable into the casement/leaf groove;

• wherein the casement/leaf groove has a first groove limb and a first groove portion and, located opposite, a second groove limb and a second groove portion;
• wherein said at least one fitting part has an elongate main body having a front side and a rear side;
• wherein the elongate main body has, on opposite longitudinal sides, a first peripheral region to engage behind the first groove limb of the casement/leaf groove and a second peripheral region to engage behind the second groove limb of the casement/leaf groove;
• and wherein a distance of a groove bottom of the first groove portion or second groove portion from a free end of a groove limb of an opposite groove portion is greater than a width of said at least one fitting part, such that said at least one fitting part is pivotable into the casement/leaf groove with the peripheral regions inserted into the groove portions.