Cubism and Cubist Artists

There is a debate over who invented Cubism, however for a painting to be a true cubist painting it must involve the three main ingredients which are:
GEOMETRICITY: Simplified objects and figures which may or may not result in the whole figure or object resembling that which we know in the natural world. It is also an approximation of the 4th dimension and is conceptual instead of perceptual reality.
PASSAGE: Overlapping and interpenetration of planes.
SIMULTANEITY: Different points of view made visible on one plane. Multiple views of objects and figures.
The argument goes that either Georges Braque or Pablo Picasso invented Cubism. Textbooks often hail Picasso's Les Demoiselles d'Avignon as the first Cubist painting as it involved the three main ingredients of Cubism; Geometricity, Simultaneity and passage. However this painting was not displayed until 1916, even though painted in 1907.
Georges Braque however delivered a series of paintings and many say that Houses at L'Estaque is the first Cubist painting which was influenced by Cezannes landscapes and painted in 1908. These paintings by Braque also urged art critic Louis Vauxcelles and Henri Mattisse to describe the paintings to be 'nothing but little cubes'. Hence the name Cubism was formed.
I think it fair to say that both Braque and Picasso created cubism, which was further developed by Juan Gris, who is described as the Third Cubist Painter. His paintings are described as more calculated than Picasso's and Braque's, with every line, shape, tone, colour and pattern being carefully refined.
There are four 'Cubism' periods.
Early Cubism or Cezannism (1908 - 1910)
Analytic Cubism (1912 - 1914)
Late Cubism (1915 - present)

Pablo Picasso: Les Demoiselles D'Avignon

Georges Braque: Houses at L'Estaque

Juan Gris: Harlequin with Guitar