> For the complete documentation index, see [llms.txt](https://lbl-2.gitbook.io/tough4-user-manual/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://lbl-2.gitbook.io/tough4-user-manual/preparation-of-model-input/keywords-and-input-data/incon.md).

# INCON

**INCON**            introduces element-specific initial conditions.

 Record **INCON.1**

                       Free format for 6 parameters

                       ELNE, PORX, stateName, (perm(I), I=1,3)

                       Or Format (A3, I2, 2I5, E15.9, A5, 3E10.4) (for mesh with 5-character gird name only)

                       EL, NE, NSEQ, NADD, PORX, stateName, (perm(I), I=1,3)

*ELNE*             the element name (for free format)

*EL*, *NE*           code name of element (for formatted input)

*NSEQ*            number of additional elements with the same initial conditions. (Not used in free format input)

*NADD*            increment between the code numbers of two successive elements with identical initial conditions. . (Not used in free format input)

*PORX*            porosity; if zero or blank, porosity will be taken as specified in block ROCKS if option START is used.

*stateName*    phase state name. It is important only when the program cannot figure out its phase state through the primary variables. The state names of each EOS module can be found in [Section 7](/tough4-user-manual/process-modeling.md).

*perm(i)*   grid block permeability, i=1,2 and 3 for x, y, z direction, respectively (optional).

Record **INCON.2**        specifies primary variables.

                       Free format for as more as 12 parameters， or Format (4E20.14)

                       Xl, X2, X3, ...

A set of primary variables for the element specified in record INCON.l. INCON specifications will supersede default conditions specified in PARAM.5, and domain-specific conditions that may have been specified in data block INDOM. Different sets of primary variables are used for different EOS modules; see the description of EOS modules in their corresponding sections. For formatted input, when more than four primary variables are used, input with multiple lines (records) are required.

 Record **INCON.3**

A blank record closes the INCON data block. Alternatively, initial condition information may terminate on a record with ‘+++’ typed in the first three columns, followed by time stepping information. This feature is used for a continuation run from a previous TOUGH3 simulation.

**Used in**: All EOS modules

**Example**:

*// an initial condition for EOS7 with 2 gases and brine, in two-phase condition (AQG)*

*INCON*

*A11 1, 3.50009259E-01, AQG                     // permX, permY, permZ may also be included in this line*        

*0.4201733403239E+07, 0.8115861911613E-01, 0.3072090574758E-05, 0.0, 65* 

*// the variables are: pressure, gas saturation, gas 2 mass fraction in  gas phase,* 

*// brine mass fraction and temperature.*