# Major & minor version (For the current version, supported by COMSOL Multiphysics version 5.5, the first two entries in a file are 0 1)
0 1 
# Number of tags (The tags are strings that function as identifiers so that objects can refer to each other)
1
# Tags (The number preceding the tag name is the number of characters in the string)
6 mesh23
# Number of types (In the current version, 0 1, of the COMSOL native data format, types are not used and are ignored.)
1
# Types
7 ignored

# -----------------------------
# --------- Object 0 ----------
# -----------------------------

# Mandatory header
0 0 1 
# Object type (String that defines which type of object follows)
4 Mesh
# Version of internal COMSOL class
4
# Space dimension
3

# Number of mesh vertices
4
# Lowest mesh vertex index
0 
# Mesh vertex coordinates (x, y, z)
0 0 0 
1 0 0
0 1 0
0 0 1

# Number of element types (0-based indexing)
1
# Element type #0
# Type name (The number preceding the tag name is the number of characters in the string)
3 tet
# Number of vertices per element
4
# Number of elements
1
# Elements
0 1 2 3

# Number of geometric entity indices (domains?)
1
# Geometric entity indices
1